Scally, one of Cork’s goalscorers in last year’s sensational senior final fightback against Dublin, scored 0-5 at Semple Stadium, as Galway were denied a third successive title.
In the process, Cork gained revenge for last year’s final defeat to the same opposition and an impressive second half display was good enough, after the sides were level at half-time.
Two goals in a minute were key as Shauna Cronin netted before Laura Cleary was alive to the chance that presented itself when captain Scally’s attempted point fell short.
Cleary raced in to fist the ball to the net from close range and Cork had breathing space, leading by 2-5 to 1-2.
The gap was out to nine, 2-10 to 1-4, before Galway rallied when Caoimhe Boyle scored the Tribeswomen’s second goal.
Megan Glynn saw a chance well saved by Mairéad O’Sullivan as Galway kept plugging away but Cork would not be denied an eighth All-Ireland title in this grade , and their first since 2011.
And they put the end result beyond any doubt with less than four minutes remaining when Hannah Looney scored a third goal for the Leesiders.
Cork had the majority of the possession, and chances, in a cagey first half. Galway did manage to break through in the 11th minute when Chelsey Blade goaled at the second attempt, after O’Sullivan kept out her initial effort.
Megan Glynn also rattled the Cork crossbar but the young Rebelettes had their own chances at the other end.
Kate Leneghan saw her 10th minute effort well saved by Dearbhla Gower and Shauna Cronin struck a shot off the base of the post and wide.
Cork registered eight first half wides as Galway, who lost Claire Dunleavy to the sin-bin for ten minutes, hung on grimly. The sides were level at 1-2 to 0-5 at the break.
Cork had raced into an early 0-2 to 0-0 lead, with Looney and captain Scally on target, but Galway responded with that Blade goal and kept in touch for the remainder of the half.
The Westerners were a point clear approaching the break but Looney scored her second point to ensure parity for Cork at the interval.
And the newly-crowned champions pushed on in the second half to prevail with nine points to spare.
E Scally 0-5 (2f), H Looney & S Cronin 1-2 each, S Cronin 1-1.
C Blade (0-1f) & C Boyle 1-1 each, C Dunleavy 0-2.
M O’Sullivan; E Spillane, E Meaney, A O’Sullivan; A Kelleher, B Casey, L Lynch; C McCarthy, E Ní Dheasmumhnaigh; E Casey, H Looney, S Cronin; K Leneghan, E Scally, L Cleary.
N Murphy for Casey (half-time), J Tonks for Kelleher (52), N Duggan for B Casey (57), L O’Neill for Cronin (59), A Nic A Bhaird for Lynch (59).
D Gower; A McBrien, S Donnellan, A Davoren; O Murphy, K Dowd, E Glynn; M Glynn, S Divilly; C Dunleavy, C Blade, S Hynes; E O’Kane, C Boyle, G Cahill.
S Molloy for Cahill (36), C Naughton for O’Kane (40), E Lowndes for Donnellan (54).
G Corrigan (Down).