The 2018 vice-captain was already contracted in 2019, but extended his deal for another three years, as he looms as one of the leading candidates for the vacant captain position.
The three-time premiership player has 186 games to his name, and has averaged 20.0 disposals, 3.7 marks, 6.0 tackles and 3.6 inside 50s per game over his career.
“We’re thrilled to have Liam recommit to the club for a further three seasons,” Hawthorn GM-Football Graham Wright told the club’s website.
“He has been a terrific contributor over the past 10 years, and he sets a great example for his teammates both on and off the field.
“Liam is 27 and would have been an unrestricted free agent next year.
“From a club perspective, it was important to lock him into a long-term deal that could see him finish his career here at Hawthorn.”