Robert Tileston Gannett (September 26, 1917 – August 26, 2012) was an American politician and lawyer.
He served in the field artillery from 1942 to 1946, including combat service in Europe in 1944 and 1945, and attained the rank of major.
Gannett was married to Sarah Alden "Aldie" Derby (December 11, 1920 – May 17, 1999), a granddaughter of President Theodore Roosevelt.
Both Gannett and his wife, Aldie, received honorary degrees from the University of Vermont.
He was affiliated with Brattleboro Memorial Hospital, the Prouty Center, the Southern Vermont Arts Council, the Vermont Community Foundation, Youth Services, the Green Mountain Club, the Brattleboro Retreat, the Snelling Center, Harris Hill and the Brattleboro Rotary Club (of which he was a founding member).