Newton Ramsay Colter (July 30, 1844 – April 6, 1917) was a physician and political figure in New Brunswick, Canada. He represented Carleton in the Canadian House of Commons from 1892 to 1896 as a Liberal member.
He was born in Sheffield, New Brunswick, the son of Alexander Colter, a native of Ireland. Colter was educated at the Sackville Academy and at Harvard University, where he received an M.D.. In 1867, he was licensed to practice by the Royal College of Physicians in London. Colter married E. Jane Hatt in 1871. He served as chairman of the Board of Health at Woodstock. Colter was defeated in a bid for reelection in 1896.