The Sydney Roosters captain stormed to an enormous victory after going into the ceremony as a red-hot favourite.
Tedesco won with a commanding 67 points, 22 ahead of Penrith Panthers halfback Nathan Cleary, who had pipped out Queenslanders Isaiya Katoa and Payne Haas (44 each) for second.
The Roosters captain, who was also named as the NRL's Captain of the Year, scored 11 tries and averaged nearly 200 metres run per game in a superb second half to the season as the Roosters stormed into the finals from a 2-5 record heading into ANZAC Day.
It was Tedesco's second Dally M victory following his award in 2019.
Warriors halfback Luke Metcalf, who was the clubhouse leader before voting went silent after Round 12, finished in eighth place after his season came to a premature end with an ACL injury.
Dally M Leaderboard
James Tedesco (67), Nathan Cleary (45), Isaiya Katoa (44), Payne Haas (44), Blayke Brailey (42), Tom Dearden (42), Reece Walsh (41), Luke Metcalf (40), Daly Cherry-Evans (39), Will Kennedy (37)
Full list of award winners
Peter Frilingos Headline Moment – The miracle of Mudgee
Provan-Summons Medal – Zac Lomax (Parramatta Eels)
Coach of the Year – Ricky Stuart (Canberra Raiders)
Rookie of the Year – Robert Toia (Sydney Roosters)
Captain of the Year – James Tedesco (Sydney Roosters)
Try of the Year – Mark Nawaqanitawase (Sydney Roosters)
Tackle of the Year – Ethan Strange (Canberra Raiders)
Ken Irvine Medal – Mark Nawaqanitawase (Sydney Roosters)
NRL Top Point Scorer – Jamayne Isaako (Dolphins)
NRL Team of the Year
Backs: James Tedesco (Sydney Roosters), Mark Nawaqanitawase (Sydney Roosters), Xavier Coates (Melbourne Storm), Kotoni Staggs (Brisbane Broncos), Stephen Crichton (Canterbury Bulldogs)
Halves: Ethan Strange (Canberra Raiders), Nathan Cleary (Penrith Panthers)
Forwards: Addin Fonua-Blake (Cronulla Sharks), Payne Haas (Brisbane Broncos), Blayke Brailey (Cronulla Sharks), Eliesa Katoa (Melbourne Storm), Hudson Young (Canberra Raiders), Erin Clark (New Zealand Warriors)
