John Crompton Weems (1778 – January 20, 1862) was an American politician.
Born in Waterloo, Calvert County, Maryland, Weems attended St. John's College of Annapolis, Maryland, and engaged in planting. He was elected to the Nineteenth Congress to fill the vacancy caused by the resignation of Joseph Kent, was reelected to the Twentieth Congress, and served from February 1, 1826, to March 3, 1829. He resumed agricultural pursuits afterwards, and died on his plantation, "Loch Eden", in Anne Arundel County, Maryland. He is interred in a private cemetery on his estate.