ESSENDON'S best and fairest winner Zach Merrett will be tied to the Bombers for at least the next five years after signing a new contract extension.

The midfielder last year signed a contract that was to end in 2018, but the club has moved to lock in the 20-year-old by adding another three years to his stay.

The new deal means he will remain a Bomber until the end of 2021 and is a big reward for his breakout season.

In just his third AFL season, Merrett was the runaway winner of the Crichton Medal after averaging 30 disposals a game.

"I'm really excited about the faith the club has shown in me, and it's great to have secured my future at Essendon for the next five years," Merrett said in a club statement. 

"The club is really well placed with (coach) John [Worsfold] at the helm. We have established a really strong culture, and with the inclusion of the 10 boys, we can't wait to get on with business and train hard over the pre-season.

"Team success is why we play the game, and I'm really looking forward to working hard and gaining as much experience from people both inside and outside the club to help the team achieve our vision."

Worsfold handed the captaincy to Merrett late in the year while stand-in skipper Brendon Goddard was injured, and said the damaging on-baller had been the club's most consistent player in its wooden-spoon season.

"It's exciting to see Zach commit to the club long term, he is an important part of our future and we look forward to watching him grow as player and leader," he said.

Merrett has played 59 games for the club since joining the Bombers via pick No.26 at the 2013 NAB AFL Draft. They gained that selection from the Western Bulldogs in a swap for former Bombers forward Stewart Crameri.

The positive news for the Bombers follows last week's confirmation that Essendon had re-signed exciting forward Jayden Laverde to a new two-year deal and that banned skipper Jobe Watson will return to the club next season.