Bannsiders boss Oran Kearney expressed his delight at the news and has challenged Shevlin to hit the heights of this season moving forward.
"We always knew Matthew had potential and when he signed, it seemed like he had been around the league for a long time after making his debut at 15-years-old," he said.
"All he needed was sustainability in terms of games and he has got that here.
"He is a number nine who can score goals and he is able to stretch defences, as well as add physicality which ticks a lot of boxes.
"His progress has probably come quicker than we thought and to score 20 goals in a season is no mean feat but he will be the first to admit that there are still aspects of his game he can get even better at.
"Matthew has a hunger to kick on, he has been brilliant for us and contracts like these are won on the pitch.
"We've probably had a frustrating second half of the season as a group but Matthew has done well individually and it's important he builds on that moving ahead.”
It has been a busy weekend for Glenavon with the club announcing no fewer than EIGHT new deals for players.
Callum Birney, Matthew Snoddy, Danny Wallace, Matthew Fitzpatrick and Peter Campbell have all agreed new four-year deal at Mourneview Park.
Conor McCloskey has extended his stay with the Lurgan Blues for another two years with Michael O'Connor and Sean Ward each agreeing new one-year deals.