This is a list of islands of Connecticut. The list does not include named minor rock outcroppings, former islands that are now connected to the mainland by landfill, and false islands that are connected by thin slivers of land to the mainland. Unless otherwise indicated, listed islands are in Long Island Sound.
| Name | Town | Coordinates | Notes |
|---|---|---|---|
| Andrews Island | Branford | ||
| Andrews Island | Stonington | ||
| Ball Island | New Haven | Mill River | |
| Barn Island | Stonington | ||
| Barton Island | Voluntown | Pachaug Pond | |
| Bear Island | Branford | Part of Thimble Islands | |
| Beers Island | Branford | Part of Thimble Islands | |
| Belden Island | Branford | ||
| Betts Island | Norwalk | Part of Norwalk Islands | |
| Bluff Island | Greenwich | ||
| Bowers Island | Greenwich | ||
| Brockway Island | Essex | Connecticut River | |
| Burr Island | Branford | ||
| Calf Islands | Greenwich | ||
| Calf Pasture Island | Norwalk | Part of Norwalk Islands | |
| Calves Island | Old Lyme | Connecticut River | |
| Candlewood Isle | New Fairfield | Candlewood Lake | |
| Canfield Island | Norwalk/Westport | ||
| Carting Island | Stratford | Housatonic River | |
| Cat Island | Branford | Part of Thimble Islands | |
| Cedar Hammock | Darien | ||
| Cedar Island | Branford | ||
| Cedar Island | Brookfield | New Milford Bay | |
| Cedar Island | Clinton | Connected to mainland by landfill | |
| Charles Island | Milford | Connected by sandbar to mainland during low tide. | |
| Chauncey Island | Ridgefield | Lake Naraneka | |
| Chimon Island | Norwalk | Part of Norwalk Islands | |
| Clam Island | Branford | ||
| Cockenoe Island | Westport | Part of Norwalk Islands | |
| Copps Island | Norwalk | Part of Norwalk Islands Connected by sandbar to Crow Island |
|
| Cove Island | Greenwich | ||
| Crab Island | Darien | ||
| Crow Island | Norwalk | Part of Norwalk Islands Connected by sandbar to Chimon Island and Copps Island |
|
| Curatole Island | New Hartford | West Hill Pond | |
| Cut in Two Island | Branford | Part of Thimble Islands | |
| Cuties Island | Stamford | Also a ghost town. | |
| Davis Island | Branford | Part of Thimble Islands | |
| Deer Island | Sherman | Candlewood Lake | |
| Deer Island | Litchfield | Bantam Lake | |
| Diving Island | Greenwich | ||
| Dodges Island | Stonington | ||
| Dog Island | Norwalk | Part of Norwalk Islands | |
| Dogfish Island | Branford | Part of Thimble Islands | |
| Duck Island | Westbrook | ||
| Duck Island | Milford | Charles E. Wheeler Wildlife Management Area | |
| Dunks Island | Old Saybrook | Wetlands off Plum Back River | |
| East Crib | Branford | Part of Thimble Islands | |
| East Stooping Bush Island | Branford | Part of Thimble Islands | |
| Elihu Island | Stonington | ||
| Enders Island | Stonington | ||
| Eustasia Island | Lyme | Connecticut River | |
| Falkner Island | Guilford | ||
| Fayerweather Island | Bridgeport | Long Island Sound near Black Rock Harbor. | |
| Fish Islands | Darien | ||
| Foskett Island | Guilford | ||
| Fowler Island | Milford | Housatonic River | |
| Fox Island | Lebanon | Williams Pond | |
| Frisbie Island | Branford | ||
| Gates Island | Groton | ||
| Gildersleeve Island | Portland | Connecticut River | |
| Goat Island | Stonington | ||
| Goodyear Island | New Milford/Bridgewater | Lake Lillinonah (Housatonic River) | |
| Goose Island | Greenwich | ||
| Goose Island | Stratford | Housatonic River | |
| Goose Island | Old Lyme | Connecticut River | |
| Goose Island | Westport | Part of Norwalk Islands | |
| Gorham Island | Westport | Saugatuck River | |
| Governor Island | Branford | Part of Thimble Islands | |
| Governors Island | Hampton | Pine Acres Lake | |
| Grass Island | Stamford | ||
| Grassy Island | Norwalk/Westport | Part of Norwalk Islands | |
| Great Captain Island | Greenwich | ||
| Great Island | Old Lyme | ||
| Green Island | Branford | ||
| Green Island | Sherman | Candlewood Lake | |
| Greenway Island | Stamford | ||
| Greenwich Island | Greenwich | ||
| Griswold Island | East Lyme | ||
| Haddam Island | Haddam | Connecticut River | |
| Hall Island | Stonington | Pawcatuck River | |
| Hen Island | Branford | Part of Thimble Islands | |
| High Island | Branford | Part of Thimble Islands | |
| Hobs Island | Groton | Thames River | |
| Holly Hock Island | Norwich | Yantic River | |
| Horse Island | Greenwich | ||
| Horse Island | Branford | Part of Thimble Islands | |
| Horse Island | Guilford | ||
| Hoyt Island | Norwalk | ||
| Huntley Island | East Lyme | ||
| Inner White Top | Guilford | ||
| Jack Island | Stamford | ||
| Johnson Island | Branford | Part of Thimble Islands | |
| Kelsey Island | Branford | ||
| Kings Island | Enfield/Suffield | Connecticut River | |
| Kitts Island | Westport | ||
| L'Hammock Island | Norwalk | Part of Norwalk Islands | |
| Lewis Island | Branford | ||
| Little Captain Island | Greenwich | ||
| Little Hammock Island | Norwalk | Part of Norwalk Islands | |
| Little Tavern Island | Norwalk | Part of Norwalk Islands | |
| Long Island | Stratford | Housatonic River | |
| Lord Island | East Haddam | Connecticut River | |
| Lovers Island | Branford | ||
| Lyddy Island | Groton | ||
| Major Island | Stonington | Pawcatuck River | |
| Marine Island | Branford | Part of Thimble Islands | |
| Marvin Island | Old Lyme | Connecticut River | |
| Mason's Island | Stonington | ||
| Menunketesuck Island | Westbrook | ||
| Mine Island | Meriden | Merimere Reservoir | |
| Minnie Island | Montville | Gardner Lake | |
| Money Island | Branford | Part of the Thimble Islands | |
| Mouse Island | Groton | ||
| Ned Island | Darien | ||
| Nells Island | Milford | Charles E. Wheeler Wildlife Management Area | |
| North Brother | East Lyme | ||
| Nott Island | Old Lyme | Connecticut River | |
| Oak Island | New Milford | Candlewood Lake | |
| Outer Island | Branford | Part of Thimble Islands | |
| Paquabaug | Roxbury | Shepaug River | |
| Peach Island | Norwalk | In Norwalk Harbor | |
| Peacock Island | Stratford | Housatonic River | |
| Peagscomsuck Island | Canterbury | Quinebaug River | |
| Pelican Island | Greenwich | ||
| Pine Island | Groton | ||
| Pine Island | New Fairfield | Candlewood Lake | |
| Pope's Flat | Stratford | Housatonic River | |
| Pot Island | Branford | Part of Thimble Islands | |
| Potato Island | Branford | Part of Thimble Islands | |
| Powder Island | New London | Thames River | |
| Ram Island | Stonington | ||
| Rat Island | Lyme | Connecticut River | |
| Rich Island | Greenwich | ||
| Rich Island | East Haddam | Connecticut River | |
| Rock Island | Stonington | ||
| Rock Island | Bridgewater | Candlewood Lake | |
| Rogers Island | Branford | Part of Thimble Islands | |
| Saint Helena Island | Branford | ||
| Salt Island | Westbrook | ||
| Sandy Hammock | Norwalk | Part of Norwalk Islands | |
| Sandy Point | Stonington | Extends into Rhode Island | |
| Scraggy Island | East Hampton | Pocotopaug Lake | |
| Sedge Island | Branford | ||
| Shea Island | Norwalk | Part of Norwalk Islands | |
| Sheffield Island | Norwalk | Part of Norwalk Islands | |
| Sherwood Island | Westport | ||
| Shore Island | Greenwich | ||
| Sixpenny Island | Groton | ||
| Smith Island | Branford | Part of Thimble Islands | |
| South Brother | East Lyme | ||
| Spectacle Island | Branford | ||
| Sprite Island | Westport | ||
| Stone Island | Clinton | ||
| Stony Island | East Haven | ||
| Sumac Island | Branford | ||
| Tavern Island | Norwalk | Part of Norwalk Islands | |
| Thatchbed Island | Essex | Connecticut River | |
| The Plans | Norwalk | Part of Norwalk Islands Connected by sandbar to Shea and Sheffield islands |
|
| Thistle Island | Sherman | Candlewood Lake | |
| Tree Hammock | Norwalk | Part of Norwalk Islands | |
| Turks Island | East Windsor | Connecticut River | |
| Tuxis Island | Madison | ||
| Tweed Island | Greenwich | ||
| Twin Islands | East Hampton | Pocotopaug Lake | |
| Twotree Island | Waterford | ||
| Umbrella Island | Branford | ||
| Vincent Island | Stamford | ||
| Walden Island | Preston | Thames River | |
| Waterford Island | East Lyme | ||
| Watts Island | East Lyme | ||
| Wayland Island | Branford | Part of Thimble Islands | |
| Wee Captain Island | Greenwich | ||
| West Crib | Branford | Part of Thimble Islands | |
| Wheeler Island | Branford | ||
| Wilcox Island | Middletown Portland Cromwell |
Connecticut River | |
| Wilson Head | Greenwich | ||
| Wintergreen Island | Winchester | Highland Lake | |
| Wood Island | Norwalk | Part of Norwalk Islands | |
| Wooster Island | Orange | Housatonic River |
|
||||||||||||||