The 21-year-old Gawn has made a successful return from a knee reconstruction that saw him miss 2012 and has played 10 senior games this season.
It was the second knee reconstruction in his career.
He also had to overcome a hamstring injury suffered in the pre-season and made his senior comeback in round four.
A livewire around the club, the 208cm Gawn is developing into a quality tap ruckman.
He can also kick goals and has managed seven from his 10 games this season when positioned as a deep forward, not a bad effort when he has had just 37 kicks.
It is understood Gawn attracted enquiries from other clubs seeking a ruckman but he chose to stay loyal to the club that drafted him with pick No.34 in the 2009 NAB AFL Draft.
"I didn’t want to go anywhere and when [acting general manager of football operations] Josh Mahoney called me last night, he said 'We managed to get a deal' it put a bit of a smile on my face, so I’m rapt," Gawn told melbournefc.com.au.
He averages 20 hit-outs a game and could end the year with claims to be the club's number one ruckman with Mark Jamar out injured for the next three weeks at least.
Jamar is tied to the club until the end of 2015 after re-signing for three years midway through 2012.
Club CEO Peter Jackson made retaining players an objective when he took over the job.
Key players Colin Sylvia and Jack Watts remain unsigned.
Sylvia, an unrestricted free agent, said two weeks ago his management was talking to Melbourne and he hoped to stay a one-club player, although he said there was no rush to sign.
Watts has played his cards close to his chest, as he is believed to be attracting interest from clubs outside Victoria. He did say the change of coach from Mark Neeld to Neil Craig made it more likely he would remain a Demon beyond 2013.
The club has formed a panel to choose the next coach with interim coach Craig among a list of potential applicants.
