St Kilda defender Dylan Roberton has committed his future to the club, signing a four-year contract extension.

The 26-year-old will now be a Saint until at least the end of the 2021 season, after enjoying a career best season in defence, which included selection in the All-Australian team.

Roberton played all 22 games for the Saints this season, averaging 23 disposals, 5.6 rebound 50s and 6.2 marks.

St Kilda CEO Ameet Bains said the club is thrilled to secure Roberton's signature for what it hopes will be a fruitful period for the club.

“Dylan is the type of player very much in demand by other clubs and we’re delighted that he has made such a long-term commitment to St Kilda,” Bains said.

“He has been an important player for a number of years, but I think this season with the addition of Jake Carlisle and Nathan Brown we’ve seen him elevate his game to another level.

“His ability to win one-on-one contests and to roll off his opponent to help out his fellow defenders is first rate, as is his ability to set up play from defence.

“He is also an integral member of our leadership group supporting Jarryn Geary and is someone who is highly respected internally.”

Roberton, who started his career with Fremantle before joining the Saints, said he is excited by what the future may bring at the club.

“I’ve loved my time at St Kilda and am really excited about what the future holds,” he said.

“As a group, we’ve been developing for a few years and I’ve enjoyed watching a number of young guys step up this year and take their footy a new level.

“We’re obviously disappointed not to be playing finals but I think we’re building nicely.

“We want to be a regular finals team and I’m determined to do what I can to help us take the next step.”

Roberton played 37 games with Fremantle after being selected with pick 49 in the 2009 AFL Draft. He then joined the Saints before the 2013 season, where he has played 87 games in five years.