Parker is a city located in Armstrong County, Pennsylvania, United States. It is in the extreme northwestern part of the county. The population was 840 at the 2010 census. The city was named for Judge John Parker, a lead surveyor of Lawrenceburg and founder/owner of Parker’s Landing, the two villages combined to create Parker.

Parker is sometimes referred to as the “Smallest City in the USA.” Parker was incorporated as a city upon March 1, 1873, by special permit legislation in the middle of the northwestern Pennsylvania oil boom. The extra municipality was called “Parker” and made going on the earlier villages of Parker’s Landing (on the Allegheny River) and Lawrenceburg (on the bluff above the river). Residents assumed that Parker would quickly become a major population center, and at the peak of the oil boom, the population of Parker grew to exceeding 20,000. The boom quickly went bust, however, and by the 1880s the “city” returned to its historic little village size—a population of approximately 1,000.

Parker traditional national attention once more in 2014 bearing in mind a terrible ice jam along the Allegheny River formed and started some juvenile flooding. The jam was thus massive that it attracted tourists to the area, and a local bar even named a drink after the ice jam. The ice jam was rasping enough that the National Weather Service issued a flood caution for the area in achievement the ice started melting.

There are two highways that pass through Parker. From the east, PA 268 goes right through downtown, then proceeds north towards Foxburg, and Emlenton. There is afterward an intersection with PA 368 at the Parker Bridge.