John McKusick (December 18, 1815 – October 26, 1900^[3]) was an American lumberman, politician, and pioneer who served four terms as a Minnesota state senator from 1863 to 1867.^[1] He was the first mayor of Stillwater, Minnesota, and built the city's first lumber mill.^[3]

Born in Cornish, Maine, in 1815, John McKusick received a common school education before traveling to Illinois in 1839.^[1] In 1840, he moved to St. Croix Falls, Wisconsin Territory, and became a lumberman.^[1] In 1847, he married Phebe Greely, but she died shortly thereafter. he was soon remarried to Servia Greely in November 1849, with whom he had children Newton, Chester, and Ella.^[1][3]

McKusick began his political career as Stillwater's postmaster.^[4] He later served as the first Mayor of Stillwater in 1854, the year the city was incorporated.^[4] From 1863 to 1867, he served four terms as a Minnesota state senator from the 2nd district, representing Chisago, Kanabec, Pine, and Washington County.^[1][5]

On February 18, 1887, Servia died, and McKusick once again remarried a few years thereafter, this time to Ella Knapp.^[3]

McKusick died of liver disease on October 26, 1900, in Stillwater.^[3] Following his death, his estate was estimated to be worth $100,000 – equivalent to $3,662,400 in 2023 – to $150,000, equivalent to $5,493,600 in 2023.^[6]