Foreign other people named John Platt, see John Platt. He was the son of Richard Platt and Mary Wood. He moved from Milford to Norwalk, and received grants of land there in 1660, 1663 and 1672.
He was a deacon of the church at Norwalk.
He was sergeant of the Norwalk Train Band. In 1680 he was one of the three commissioners appointed to lay out the plantation north of Stamford.
In 1687, he was appointed one of the three commissioners chosen to lay out Danbury.