STAR St Kilda defender Dylan Roberton has turned his back on rival interest and inked a four-year deal to keep him at the Saints until the end of 2021. 

Roberton started the season on fire and was nominated in the Virgin Australia AFL All Australian squad after averaging 23 disposals, six rebound 50s and 474m gained. 

It was the first time he played every game in a year. 

Roberton, 26, told saints.com.au he wanted to help the club reach finals for the first time since 2011. 

"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."

A mid-season change of management was part of the reason for the hold-up in negotiations.

Chief operating officer Ameet Bains said Roberton was a pivotal member of the backline.

"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 was introduced to the leadership group at the start of the year.

He was drafted by Fremantle in 2009 at pick No.49, before asking to return home to Victoria in 2012, and was signed by the Saints as a delisted free agent.

The backman grew up close to the club's base in Seaford.