Hartwick is a former townsite in Delhi Township, Delaware County, Iowa, United States.

The community was on the Maquoketa River, at the crossing of 220th Avenue, southwest of Delhi.

The Hartwick post office opened on January 1, 1853, and operated until September 24, 1861.

[2] John W. Clark founded and platted Hartwick in Section 30 of Delhi Township in December 1858.

[4] Hartwick still appeared on maps in the early 20th century,[5] but with decreasing frequency.