New York State Route 159 (NY 159) is a 13.52-mile-long (21.76 km) east–west state highway in New York, running from the town of Duanesburg through Mariaville Lake to the hamlet of Rotterdam, just outside the city of Schenectady.

A two-lane highway for all of its length, it is entirely located in Schenectady County.

After heading south for about a mile past the lake, NY 159 turns eastward.

Three miles later, a long gentle curve toward a more southerly direction has it heading downhill until another turn takes it to its Thruway overpass.

[3] NY 159 was assigned to its current alignment as part of the 1930 renumbering of state highways in New York and has not had any major changes since.