The Carnacon starlet kicked 2-11 as Mayo, who were reduced to 14 players when skipper Claire Egan picked up a second sin binning in the 39th minute, cantered to the title.
But the performance of Staunton was the real talking point as she dragged Mayo back from an early deficit to a 16-point victory.
Trina McNicholas and Fiona McHale also netted. Edel Concannon and Deirdre Brennan got the Galway goals.
Scorers for Mayo: C Staunton (2-11, 7fs); F McHale (1-1); T McNicholas (1-1); D Doherty (0-2); M Carter (0-2)
Scorers for Galway: E Concannon (1-1); D Brennan (1-0); G Conneally (0-2); T Leonard (0-2, 1f); C Hehir (0-1); G Joyce (0-1f)
MAYO: N Tarpey; A Bell, N Tierney, L Ryder; S Tierney, C Egan, C Connolly; M Carter, C McManamon; F McHale, C Staunton, Y Byrne; T McNicholas, D Doherty, N Kelly.
Subs: A Gilroy for Ryder (21), S Rowe for Kelly (42), A Roddy for Connolly (55), A Brennan for Doherty (56), O Conlon for Staunton (57).
GALWAY: L Murphy; M Coyne, E Curley, S Divilly; B Hannon, S Conneally, S Burke; A Daly, C Hehir; C Cooney, D Brennan, L Leonard; T Leonard, G Joyce, G Conneally.
Subs: E Concannon for Conneally (40), T Mullins for L Leonard (44), M Burke for T Leonard (45), E Gannon for Cooney (46), B Walsh for Joyce, (46).
Referee: Shaun Duane (Kildare).