Greens Ledge Light
|Year first constructed||1902|
|Year first lit||1902|
|Foundation||Cast Iron with Concrete caisson|
|Tower shape||Conical "Spark Plug"|
|Markings / pattern||Upper white, lower brown on black cylindrical pier|
|Height||52 feet (16 m)|
|Focal height||62 feet (19 m)|
|Original lens||5th order Fresnel lens (replaced with a 4th order)|
|Range||White 18 nautical miles (33 km; 21 mi), Red 15 nautical miles (28 km; 17 mi)|
|Characteristic||alternating red and white flash every 12s|
Greens Ledge Lighthouse
|Nearest city||Rowayton, Connecticut|
|Area||less than one acre|
|Architect||Philadelphia Construction Co.|
|Governing body||COAST GUARD|
|MPS||Operating Lighthouses in Connecticut MPS|
|NRHP Reference #||
|Added to NRHP||May 29, 1990|
Greens Ledge Lighthouse is a sparkplug lighthouse in Connecticut, United States, off the southwest end of the Norwalk Islands, Long Island Sound, near Norwalk, Connecticut. It is on north side of the west end of Greens Ledge, west of Norwalk Harbor a mile south of the entrance to Five Mile River at Rowayton, and just over a mile southwest of Sheffield Lighthouse.
When it was built in 1902, the "sparkplug" style lighthouse replaced the Sheffield Island Light. At first it had a fifth order Fresnel lens. Three months after it was first lit, it was upgraded to a fourth order Fresnel lens. The 52-foot (16 m) tower developed a tilt over time and the keepers also complained the station’s generators caused the furniture to move to one side of the tower. They solved the problem by keeping all the furniture on one side. The light was automated by the United States Coast Guard in 1972. The light is an active aid to navigation and is not open to the public.
The light was added to the National Register of Historic Places as Greens Ledge Lighthouse on May 29, 1990, reference number 89001468.
- Light List, Volume I, Atlantic Coast, St. Croix River, Maine to Shrewsbury River, New Jersey (PDF). Light List. United States Coast Guard. 2009. p. 191.
- "Historic Light Station Information and Photography: Connecticut". United States Coast Guard Historian's Office. 2009-08-08.
- "National Register Information System". National Register of Historic Places. National Park Service. 2009-03-13.
- "Greens Ledge Lighthouse, CT". LighthouseFriends.com. September 12, 2006.
- Fenwick, Alexandra (September 10, 2006). "A long crawl: Swimmers compete in annual Sound race". The Advocate (Stamford, CT (Stamford edition)). pp. A3, A9.
-  Library of Congress photographs of Greens Ledge Lighthouse, page 1 of 2