Palmer, the US-based world number six from New South Wales, reached his 51st Tour final after beating Spaniard Borja Golan, winner of last week's Motor City Open in Detroit.
It was Barker, the second seed from London, who ensured a new winner of the event in its fourth year in Halifax when he defeated Dutch defending champion Laurens Jan Anjema in the other semi.
But Palmer proved his first seed status with a near flawless display in the final. The favourite's total unforced error count averaged only one per game, an almost impossible task to counter - even for another top-ten player like Barker.
And after 44 minutes, 32-year-old Palmer celebrated the victory which takes his PSA Tour haul to 24 titles - and stretches his lead as the current player with the most Tour titles to two ahead of second-placed Amr Shabana.
Semi-finals:
[1] David Palmer (AUS) bt [3] Borja Golan (ESP) 11-8, 11-7, 6-11, 11-8
[2] Peter Barker (ENG) bt [4] Laurens Jan Anjema (NED) 6-11, 12-10, 11-8, 11-7
Quarter-finals:
[1] David Palmer (AUS) bt [Q] Shawn Delierre (CAN) 11-3, 11-3, 11-3
[3] Borja Golan (ESP) bt [5] Cameron Pilley (AUS) 13-11, 7-11, 4-11, 11-2, 13-11
[4] Laurens Jan Anjema (NED) bt [7] Chris Ryder (ENG) 11-6, 11-4, 11-4
[2] Peter Barker (ENG) bt [6] Miguel Angel Rodriguez (COL) 11-2, 11-5, 11-7
1st round:
[1] David Palmer (AUS) bt Tom Richards (ENG) 11-3, 11-9, 11-6
[Q] Shawn Delierre (CAN) bt [8] Kashif Shuja (NZL) 11-9, 11-5, 6-11, 11-9
[3] Borja Golan (ESP) bt [Q] Stephen Coppinger (RSA) 11-3, 11-6, 11-6
[5] Cameron Pilley (AUS) bt Julian Illingworth (USA) 11-2, 13-11, 11-6
[7] Chris Ryder (ENG) bt Martin Knight (NZL) 4-11, 11-7, 9-11, 11-6, 11-6
[4] Laurens Jan Anjema (NED) bt Jan Koukal (CZE) 11-5, 11-6, 11-6
[6] Miguel Angel Rodriguez (COL) bt [Q] Wade Johnstone (AUS) 11-8, 11-9, 11-7
[2] Peter Barker (ENG) bt [Q] Liam Kenny (IRL) 11-6, 11-5, 11-6
Issued by iSPORTmedia