John Runk (July 3, 1791 – September 22, 1872) was an American Whig Party politician, who represented New Jersey's 3rd congressional district in the United States House of Representatives from 1845 to 1847.
Runk was born in Milltown (later, Idell), Hunterdon County, New Jersey.
He attended the district schools and took charge of the mills and general store on his father's property in Milltown.
A majority of the investigating committee found in Runk's favor, but when his case came before the full House, a motion to remove him and leave the seat vacant failed only after the Speaker cast a tie-breaking vote in his favor, making this the closest contested election in the history of the House.
He moved to Lambertville, New Jersey in 1854 and engaged in the milling business and mercantile pursuits.