Peter Van Alstine (Vanalstine) (1743–1811) was a farmer, soldier and political figure in Upper Canada.
He helped settle a group of Quakers and a number of former Loyalist soldiers in the Bay of Quinte area.
Van Alstine first settled in Adolphustown Township in Upper Canada.
He was elected to the Legislative Assembly of Upper Canada to represent Prince Edward and Adolphustown in a 1793 by-election after his neighbour Philip Dorland was unseated because he could not take the oath of office as a Quaker.
Van Alstine later moved to Marysburgh Township in Prince Edward County near the current site of Glenora where he built a gristmill in 1806, which is still known today as Van Alstine's Mill.