Grimsby were keen to keep the 24-year-old, who can operate as a centre forward or on either wing and netted 16 times in 72 appearances for them, but he rejected a new contract at the end of last season.
Coulson is York boss Gary Mills' fourth signing this month as he prepares his squad for life in the npower Football League after last month's play-off final win over Luton.
The Minstermen have already captured Lee Bullock from Bradford, Oli Johnson from Oxford and John McReady from Darlington.


 





