FREMANTLE has locked in coach Ross Lyon until 2020 after extending his existing contract by three more years.

Lyon was contracted until the end of 2017 but at the Dockers' season launch on Thursday morning, CEO Steve Rosich announced the coach had agreed to a longer deal. 

Lyon has coached Fremantle since 2012, guiding the club to four successive finals series, a maiden Grand Final in 2013 and an inaugural minor premiership in 2015. 

He arrived at the Dockers after five years in charge at St Kilda, where he coached the Saints to Grand Finals in successive years, narrowly failing to win the club's second premiership. 

Lyon said the long-term extension to his current deal meant there was no excuses for him not to deliver the elusive premiership the Dockers crave.

"Ultimately none of us are satisfied with where we're at," Lyon said.

"We're certainly aiming for a premiership and you don't shy away from that.

"Particularly by the end of this tenure, I'll have no excuse to not have achieved that because we're fully resourced, fully supported and I've certainly got a timeframe where I can make short-term and long-term decisions to get us where we want to be."

Lyon was confident that the Dockers would be a contender again in 2016. 

"I'm sure that we'll be there when the whips are cracking," he said.

Rosich said the securing Lyon long-term gave the Dockers the best chance for sustained success.

"This important decision enables us to take a long-term view across our football operations and how we best support our players for today and for the future," Rosich said.

"Apart from securing the services of our highly regarded and experienced senior coach, it allows the club and Ross to plan with certainty well into the future for our football operations, including the coaching team, players and support staff."

Lyon is one of only 37 men to have coached 200 games or more in AFL/VFL history. He has coached 218 games with a winning percentage of 66 per cent.