Poestenkill is a town in Rensselaer County, New York, United States.

[9][10] It seems more likely that the creek was named after the nickname Poest for the 17th-century local farmer and miller Jan Barentsen Wemp, who had a pimple (poest) or had difficulty breathing (poesten = to breathe); he owned a farm and a mill on the Poestenkil creek.

One, named Benjamin Cotterel, is said to have carried the first wheelbarrow of earth to Bunker Hill.

[6] The first school in the area was established in or soon after 1788 on land set aside for that purpose by Stephen Van Rensselaer III.

[6] During the American Civil War, many of Poestenkill's men served with the Union's forces; twelve who died in action were Daniel M. Horton, Philip Amidon, Daniel Morrison, John Wagoner, George Bradt, Dexter Randall, William H. H. Wood, Martin Larabee, Willard Bailey, W. L. Robbins, George Simmons, and William H.

[6] Future president James A. Garfield considered a job as high school principal in Poestenkill in 1856, though lost it to another applicant.

[13] Poestenkill celebrated its sesquicentennial (150th anniversary) in 1998, with several events including a Revolutionary War reenactment, antique car show, a parade, and a historical display.

The eastern and central portions of the town are part of the Rensselaer Plateau.