The former Melbourne midfielder’s move west was confirmed on Friday morning when Fremantle officially lodged the paperwork at the commencement of the Gillette Trade and Free Agency Period.
The 27-year-old advised the Demons on Thursday of his intentions to join Ross Lyon’s side.
He said it had been a tough decision to leave, but one he felt was best for his career.
“Fremantle are a good fit for me, based on where I’m at with my football career,” Sylvia said.
Fremantle general manager of football operations Chris Bond said the acquisition of Sylvia was a positive one for the club.
"We see Colin as a mature, bigger-bodied player who can really add to the football club," Bond said.
"All the research we did into Colin, when we spoke to him and we spoke to other people about him, was extremely positive.
"We think his experience and his work-rate is really going to add to our midfield."
Sylvia was the third pick in the 2003 National Draft and made his debut in round 9, 2004.
He has kicked 129 goals in 157 games with Melbourne and had a very consistent year in 2013, playing 19 games and finishing fifth in the club's best and fairest.
