The 22-year-old won Essendon's Crichton Medal from defender Cale Hooker in front of a sell-out crowd at Crown Palladium.
The honour followed on from his excellent season that not only saw him named on the wing in the All Australian team last month but also as captain of the under-22 team for the second straight year.
Heppell polled 520 votes to win from Hooker (354), with Brendon Goddard third with 279.
Hooker was also a first-time All Australian this year, named in the back pocket.
Michael Hibberd (277) and David Zaharakis (250) rounded out the top five, with Michael Hurley (242) and Patrick Ryder (241) next.
Thompson said Heppell, who played 22 games and averaged more than 28 touches, had gone to another level this season in the absence of Jobe Watson for two months.
He started the season across half-back but moved into the midfield on a more permanent basis as the year progressed, where he became the most prolific Essendon player when it came to tackles.
"Dyson is a terrific young man and he's a really easy player to coach," Thompson said.
"He is only young, but has started to prove he will be a future leader of this football club.
"With Jobe out injured earlier this year, Dyson stood up time and time again, and from a coaching perspective that was great to watch. He demands the best from himself and his teammates.
"He's been close the last couple of seasons, so to win this award, I think, is reward for his hard work and preparation. He is going to be exciting to watch over the next few seasons."
Heppell was also named best clubman and won the cheer squad award.
Dyson Heppell - 520
Cale Hooker - 354
Brendon Goddard - 279
Michael Hibberd - 277
David Zaharakis - 250
Michael Hurley - 242
Patrick Ryder - 241
Mark Baguley - 240
Paul Chapman - 231
Bruce Heymanson best team player – Heath Hocking
Bill Hutchison community award – Cale Hooker
Cheersquad award – Dyson Heppell
RA Freeman VFL best and fairest – Ariel Steinberg
John Kilby best clubman – Dyson Heppell
Matthew Lloyd leading goal kicker – Joe Daniher
Lindsay Griffiths rising star – Joe Daniher
Most improved player – Travis Colyer
Adam Ramanauskas most courageous player – Mark Baguley
Best defensive player – David Myers