House at 251 Rocklyn Avenue

House at 251 Rocklyn Avenue is a historic home located at Lynbrook in Nassau County, New York. It is an L-shaped dwelling with 2-story central section, a 2-story addition to the east, and $1 1/2$-story addition to the west with a 1-story rear addition and cross gable roof. The oldest section, the west section, was built about 1793. A single-story, partially enclosed porch extends across the center section.

It was listed on the National Register of Historic Places in 2008.