Discover the Top 10 Most Populated Islands in the U.S. (Manhattan is NOT #1!)

Written by Lev Baker
Updated: July 12, 2023
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These are the 10 most populated islands in the United States
These islands represent the amazing diversity of the American landscape.

Do you know which island in the United States is the most populated? If Manhattan immediately comes to mind, get ready for a revelation! In this article, we will get to know America’s most densely inhabited islands. From cultural hubs to hidden gems, each island holds its own charm. 

Together, we’ll explore the unexpected stories, astonishing diversity, and intriguing statistics behind the top ten most populated islands in the U.S.

1. Long Island — 8,063,232

the buildings of long island in front of east river at twilight

The number one most populated island in the U.S., Long Island has a rich history.


Long Island, situated in southeastern New York State, stands as a densely populated island that holds immense significance within Metropolitan New York. With a staggering populace surpassing eight million, it proudly claims the title of the most populous island in the United States and ranks 18th globally in terms of population.

This extraordinary island boasts a rich history stretching back to the 17th century when European settlers first arrived on its shores. However, it was the advent of the 19th-century railroad infrastructure that truly left its mark, catalyzing the island’s growth and transformation. 

Beyond its vibrant city life, Long Island is renowned for its stunning beaches, delectable bagels, and the musical legacy of the illustrious Billy Joel. Moreover, this captivating place offers a visual feast with captivating landmarks like the grand Oheka Castle, the opulent Vanderbilt estate, and the historic Montauk Lighthouse. Much like the famed Long Island iced tea, this remarkable island combines a diverse array of elements into one extraordinary destination!

Wildlife in Long Island

The island’s natural beauty is a treasure for wildlife enthusiasts. You can observe magnificent creatures such as the long-tailed duck, the piping plover, harbor seals, white-tailed deer, elusive red foxes, Cooper’s hawks, and painted turtles. Additionally, the island’s shores provide a haven for sea turtles.

2. Puerto Rico — 3,285,874

Colorful houses line the hillside over looking the beach in San Juan, Puerto Rico

Puerto Rico is a U.S. territory with beautiful beaches and vibrant festivals.

©Martin Wheeler III/

The second most populated island in the US is none other than the breathtaking Puerto Rico. While not officially a state, Puerto Rico is a territory of the United States. Situated about 1,000 miles southeast of Miami, Florida, this vibrant destination is home to approximately 3.2 million residents.

Back in 1493, the legendary Christopher Columbus made his mark here during his second voyage to the New World. Initially named San Juan Bautista, this enchanting island soon became known as Puerto Rico, meaning “rich port” in Spanish. Fast forward to 1898, Puerto Rico officially became a U.S. territory after the Spanish-American War. This brought some self-rule and limited representation in Washington.

From its breathtaking beaches to its vibrant festivals, this island has it all. Prepare to be captivated by Puerto Rico’s 300 miles of untouched coastline, inviting you to indulge in leisurely strolls along its sandy shores.

Wildlife in Puerto Rico

Puerto Rico is a wildlife enthusiast’s dream come true. Dive into the depths and discover playful dolphins, awe-inspiring sharks, and majestic whales. Puerto Rico is also home to a whopping 13 bat species. And bird lovers, rejoice! With around 350 bird species fluttering about, including 18 exclusive to Puerto Rico, you’re in for a treat. Just remember to give the Caribbean reef shark its space when you’re exploring the surrounding waters.

3. Manhattan — 1,694,251

New York City panorama skyline at sunrise. Manhattan office buildings / skysrcapers at the morning. New York City panoramatic shot.

Surprisingly, Manhattan is not the number one populated island in the United States.


Manhattan, often hailed as the financial, cultural, and media hub of the world, proudly houses the headquarters of the United Nations. Although commonly believed to be the most populous island in the United States, it actually stands as the third most populous. 

Nevertheless, Manhattan boasts an impressive population density, with 1,694,251 individuals calling its 22.83 square miles of land their home, according to the 2020 census.

Situated near the southern tip of New York state, Manhattan holds a significant place in history as it was once part of the Lenapehoking territory, which was inhabited by the Wappinger and Munsee Lenape tribes. 

Spanning from Inwood to the Financial District, Manhattan has established itself as the thriving epicenter of global commerce. Millions of people visit Manhattan annually to visit iconic buildings such as Empire State!

Wildlife in Manhattan

Manhattan may be a busy city, but it’s also a surprising habitat for various wildlife. You can catch a glimpse of different bird species, such as great blue herons, warblers, and red-tailed hawks.

Squirrels are a common sight, happily running around in trees and parks. Raccoons and opossums sometimes also show up in the more peaceful parts of the city. And don’t forget coyotes! Yes, you read that right. Coyotes often make appearances in Manhattan and other areas of New York City!

4. Oahu — 1,016,508

Ho'omaluhia Botanical Park at Oahu Island in Hawaii, United States.

The most populated island in Hawaii, Oahu is not only a vacation destination but also home to over a million people.

©Cautron Live/

Oahu is a vibrant island home to more than one million people. This makes Oahu not only the most populous island in Hawaii but also the fourth most populated island in the entire United States. Situated along the southeastern coast lies the state capital, Honolulu, bustling with vibrant energy.

Western explorers first laid eyes on Oahu during Captain James Cook’s Pacific expedition in 1778, and the island witnessed its first landing in 1779. This marked the beginning of a transformative era, as whaling ships and missionaries arrived, leaving a profound impact on the lives of the Native Hawaiians. 

Oahu beckons with its captivating blend of natural wonders, cultural heritage, and remarkable history. Dubbed the “Gathering Place,” Oahu stands as the most sought-after destination in Hawaii, enticing countless visitors to its shores.

This paradise island is renowned for its captivating state capital of Honolulu, the poignant historical significance of Pearl Harbor, the legendary North Shore, famous for its world-class surfing, and the iconic Waikiki Beach. Nature blesses Oahu with two dormant volcanoes, Koolau and Waianae, adding an awe-inspiring touch to the island’s allure.

Wildlife in Oahu

The pristine coastal waters surrounding Oahu provide a haven for various marine mammals, including the endangered Hawaiian monk seal, dolphins, and whales. The island is also home to majestic sea turtles, many seabird species, and a plethora of unique endemic forest birds that exist solely within the diminishing native forests.

Dive into the vibrant underwater world and encounter approximately 680 species of fish that call the waters surrounding the Hawaiian Islands their home.

5. Staten Island — 495,747

Staten Island, New York

Known for museums, parks, and historical sites, Staten Island is the fifth most populated island.

©Jayne Lipkovich/

Staten Island is linked to Manhattan through the renowned Staten Island Ferry, serving as a means of transportation for both people and vehicles.

Home to a population of approximately 495,747 individuals, Staten Island is another populous island in the state of New York!

During the significant merger of 1898, Staten Island became an integral part of New York City, formerly known as the Borough of Richmond. However, in 1975, the borough underwent a name change, adopting the moniker of Staten Island.

Renowned for its lush captivating museums, green parklands, and historical sites, Staten Island has rightfully earned the reputation as the “borough of parks.” This title is owed to the abundant natural spaces it offers, including High Rock Park, Greenbelt, Clove Lakes, and Lemon Creek Park. 

Here’s an interesting fact: A remarkable 34.7% of Staten Island’s residents can trace their roots back to Italian ancestry, lending a distinct cultural flavor to the borough.

Wildlife in Staten Island

Staten Island’s wildlife is teeming with a fascinating array of creatures. From majestic white-tailed deer and elusive red foxes to the melodic songs of colorful bird species like cardinals and blue jays, the borough offers a delightful experience for nature enthusiasts. Keep your eyes peeled for charming eastern cottontail rabbits, graceful great blue herons, and the occasional visit from a majestic bald eagle.

6. Island Of Hawaii — 200,629

Anaehoomalu (A-bay) Waikoloa Big Island Hawaii

Boasting waterfalls, cliffs, beaches, and more, the Island of Hawaii has a history dating back to the 9th century.


The Island of Hawaii, also known as the Big Island, is the southeasternmost gem among the Hawaiian Islands. Boasting a population of 200,629 individuals according to the 2020 census, it accounts for merely 13% of the entire state’s inhabitants.

The captivating history of Hawaii begins with the arrival of Polynesians. A subsequent wave of settlement occurred in the 9th or 10th century, marking the island’s cultural evolution. It was on the Big Island that the first luakini heiau, an ancient ceremonial structure intertwined with worship and human sacrifice, was constructed.

From awe-inspiring waterfalls and majestic cliffs towering over crashing waves to rivers of molten lava and snow-capped peaks, this sacred land unveils a pack of indescribable beauty. Within its borders, one can traverse lava fields, explore lush rainforests, and discover valleys teeming with life.

With a staggering influx of 1.5 to 1.7 million travelers annually, the island offers an unparalleled experience. Beyond its natural wonders, Hawaii holds a treasure of historical sites that captivate the imagination.

Wildlife on Big Island

The Big Island’s isolation has fostered the evolution of numerous unique species found nowhere else on Earth. From the graceful green sea turtles and elegant manta rays gracing the waters to the spinner dolphins, monk seals, and even the majestic sharks, the island teems with a diverse array of wildlife both on land and in the sky.

7. Guam — 168,801

Guam Ocean Sunrise in hotel

Guam is a United States territory with beautiful vistas and a strong military presence.


As an organized, unincorporated territory of the United States, Guam boasts breathtaking natural beauty and a thriving culture. This enchanting island paradise is a cherished home to around 168,801 residents, making it one of the most densely populated islands in the United States.

On June 21, 1898, the United States achieved victory by capturing this island. Eventually, through the Treaty of Paris in 1898, Spain officially handed over Guam to the U.S., marking the beginning of a new era under the American administration, starting from April 11, 1899.

When it comes to dreamy destinations, Guam is unrivaled. Imagine pristine white sand beaches and azure waters inviting you to unwind and escape the hustle and bustle of city life. Whether you’re seeking a family-friendly getaway, a romantic honeymoon spot, or an underwater adventure as a diving enthusiast, Guam has it all.

But Guam isn’t just about picture-perfect landscapes. The island thrives due to its strong military presence and dynamic economy that fuels its growth and development. 

Wildlife in Guam

Like any paradise, Guam faces challenges. Invasive species have posed significant threats to the island’s unique biodiversity. The brown tree snake, for instance, caused the unfortunate extinction of endemic bird species.

Nevertheless, Guam remains a sanctuary for captivating wildlife, including the leatherback sea turtle, gadwall, Eurasian wigeon, pygmy killer whale, and little tern.

8. Maui — 164,221

East Maui on the island of Maui

The third-largest Hawaiian island, Maui offers encounters with various wildlife, including humpback whales.


Maui is an enchanting island that captivates hearts with its natural wonders! Known as the third-largest island in Hawaii, Maui is also the eighth most populous island in the United States, with around 164,221 residents who proudly call this paradise their home.

Maui’s history dates back to the ancient Polynesians who settled here around AD 700. It was in the 14th century that the visionary Hawaiian chief, Piilani, constructed the magnificent Piilanihale Heiau, the largest stone temple on the island, as well as an impressive road network. While whaling declined in the 1860s, the rise of the sugar industry became a pivotal economic force. Eventually, tourism took over as the primary driver of Maui’s economy, surpassing sugar.

Maui is renowned for its pristine beaches, which have gained worldwide acclaim. The sacred ʻĪao Valley provides a tranquil escape, while the winter months offer the opportunity to witness the awe-inspiring migration of humpback whales. Indulge in the farm-to-table culinary delights that the island offers, and be sure to witness the breathtaking sunrises and sunsets from the majestic Haleakalā.

Wildlife in Maui

Maui’s wildlife is equally captivating. Keep an eye out for the Hawaiian green sea turtles, the humpback whales, the Hawaiian spinner dolphins, the mongoose, and the nene goose, Hawaii’s state bird.

9. Alameda Island — 78,280

Afternoon aerial view of Alameda Island and the San Francisco Bay in California.

Alameda was created when a canal opened up in 1902.


Nestled in the picturesque San Francisco Bay in California, Alameda Island beckons visitors with its unique charm. Although a small portion of the island’s western tip technically belongs to San Francisco, it remains uninhabited and is not separately managed. Alameda Island, boasting a population of around 78,280 residents, is the ninth most populous island in the United States.

Interestingly, Alameda Island was not originally an island. It was created in 1902 when a canal was opened on its southern side to maintain a clear shipping route in the estuary to the north and improve tidal scouring. Through strategic landfill efforts, the island expanded until it reached the San Francisco border.

Alameda Island is renowned for its inviting beaches, captivating bird refuges, and a network of scenic bicycle and pedestrian paths. Nature enthusiasts can enjoy the island’s natural open spaces and indulge in leisurely picnics along the extensive waterfront areas. The shoreline parks, extending over more than six miles, run alongside the picturesque San Francisco Bay and the San Leandro Marina. They provide stunning views of the iconic San Francisco skyline and the magnificent East Bay hills.

Wildlife on Alameda Island

The island’s parks and natural areas offer refuge to many bird species, including majestic herons, colorful warblers, and graceful hawks. Exploring the island’s shores, you may come across playful seals basking in the sun. Additionally, the island’s green spaces provide habitat for squirrels, rabbits, and other small mammals.

10. Kauai — 73,298

Na Pali coast, Kauai, Hawaii view from sea sunset cruise tour. Nature coastline landscape in Kauai island, Hawaii, USA. Hawaii travel.

Also called the “Grand Canyon of the Pacific”, Kauai has everything from mountains and waterfalls to cliffs.


Situated in the stunning Hawaiian archipelago, Kauai is the fourth-largest Hawaiian island. Home to 73,298 residents as of 2020, this idyllic paradise proudly claims its spot as the tenth most populated island in the United States.

This extraordinary island is the oldest inhabited land among its counterparts, a testament to its enduring history. What makes Kauai even more intriguing is its unique resistance to the legendary King Kamehameha’s conquest and his ambitious quest to unite the entire archipelago.

Kauai is a paradise of stunning wonders, from the awe-inspiring Waimea Canyon, often called the “Grand Canyon of the Pacific,” to the scenic Coconut Coast. Explore magnificent mountains, cascading waterfalls, white sand beaches, sugarcane fields, and the dramatic cliffs of the Na Pali coast.

Wildlife in Kauai

The island is home to a vibrant array of wildlife, offering unique encounters with nature. Look out for the endangered Hawaiian monk seal, the nene goose, dolphins, whales, Hawaiian crow, and the Hawaiian stilt.

Summary of the Top 10 Most Populated Islands in the U.S.

1.Long IslandNew York8,063,232
2.Puerto RicoPuerto Rico3,285,874
3.ManhattanNew York1,694,251
5.Staten IslandNew York495,747
6.Island Of HawaiiHawaii200,629
9.Alameda IslandCalifornia78,280

The photo featured at the top of this post is © Maridav/

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About the Author

Lev is a writer at AZ Animals who primarily covers topics on animals, geography, and plants. He has been writing for more than 4 years and loves researching topics and learning new things. His three biggest loves in the world are music, travel, and animals. He has his diving license and loves sea creatures. His favorite animal in the world is the manta ray.

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