The 6'4 striker has joined on a one year deal with an option of a second after the Sky Blues paid a nominal (£50k according to rumours) amount for the Wolverhampton born player who played for Aidy Boothroyd last season.
Platt has played for Walsall, Rochdale where he scored 30 goals in 166 appearances, Notts County, Peterborough, MK Dons before he joined Colchester in 2007, making 124 appearances and scoring 25 goals.