Hayes, who also won the count in 2003, polled 528 votes to finish comfortably ahead of fellow midfielder Leigh Montagna (451).
Brendon Goddard and Sam Gilbert (435) tied for third place, while Nick Dal Santo and Adam Schneider (399) were equal fifth.
Hayes played all but one of St Kilda's 26 games in 2010, with his leadership, work rate and ability to win contested possessions crucial to the club's progression to the finals.
The 30-year-old captained the Saints during Nick Riewoldt's three-month absence through injury, and won the Norm Smith Medal in the drawn grand final against Collingwood.
He was named in the preliminary All Australian squad, but missed selection in the final team.
Hayes gave special mention to coach Ross Lyon in his acceptance speech.
"I think we've definitely got the best coach in the AFL," Hayes said.
"I think for five or six weeks in a row there was one thing or another and Ross got the boys in and said, 'we've worked too long and too hard and this is what we're going to do this year. This is the direction we're going,' and it gave the boys a real lift.
"It's a pleasure to play underneath Ross."
Goddard spoke about the burning desire for a premiership that drove the club.
"We want it, we want it real bad so stick by us," he told the Saints fans.
"If we don't achieve it, we'll bloody die trying."
In the evening's other presentations, Riewoldt received the Robert Harvey most professional player award for his diligence in recovering from his serious hamstring injury, and defender James Gwilt took out the most promising player award.
Gwilt's eighth-place in the best and fairest count marked his first finish in the top 10.
2010 TREVOR BARKER AWARD
1. Lenny Hayes - 528 votes
2. Leigh Montagna - 451
3. Sam Gilbert, Brendon Goddard - 435
5. Nick Dal Santo, Adam Schneider - 399
7. Sam Fisher - 378
8. James Gwilt - 348
9. Stephen Milne - 329
10. Jason Blake - 312
