Union Gap is a city in Yakima County, Washington, United States.

The town is named for a water gap formed by the Yakima River between the Rattlesnake Hills and Ahtanum Ridge.

When bypassed by the Northern Pacific Railroad in December 1884, over 100 buildings were moved with rollers and horse teams to the nearby site of the depot.

[2] Liberty Bottleworks, a water bottle manufacturer, operates out of a plant in Union Gap that employs 18 people.

There were 2,275 housing units at an average density of 407.9 inhabitants per square mile (157.5/km2).

There were 2,173 housing units at an average density of 430.3 inhabitants per square mile (166.1/km2).

23.5% of all households were made up of individuals, and 8.9% had someone living alone who was 65 years of age or older.

26.0% of all households were made up of individuals, and 10.4% had someone living alone who was 65 years of age or older.

Union Gap is the namesake of Gary Puckett & The Union Gap, a nationally successful pop group of the late 1960s (Puckett grew up in the adjacent city of Yakima).