St Mary's is an electoral ward of Trafford covering most of the southern half of Ashton upon Mersey in Sale.
The ward was created in 2004 largely from the old St Martins ward and parts of the old Mersey St Mary's ward.
As of 2022, the councillors are Rob Duncan (Conservative), Dan Bunting (Conservative), and John Holden (Conservative).
indicates seat up for re-election.