COLLINGWOOD has officially locked away coach Nathan Buckley for the next three seasons.

As flagged by, Buckley has added 2020 and 2021 to his existing deal for this season.

Just 18 months after surviving an intense whole-club review and earning a two-year contract extension until the end of the 2019 season, Buckley's new commitment comes off a Grand Final berth last year.

"With 22 days to go, we did want to lock and load some of our off-field leadership as well," chief executive Mark Anderson told the club's playing group.

"I'm rapt to announce, on behalf of the board, that we've extended Bucks for season 2020 and 2021.

"We're not at our destination, (in) 22 days we start that next chapter. What we're absolutely sure about is that Bucks is the person that's going to lead us through the next three seasons."

The three-year extension will ensure Buckley becomes a 10-year coach at the Pies, the tenure as AFL great Leigh Matthews (1986-1995) enjoyed.

Jock McHale (1912-1949), Phonse Kyne (1950-1963) and Mick Malthouse (2000-2011) sit among the club's longest serving coaches.