The 31-year-old restricted free agent played 184 games for the Crows and a total of 201 AFL games after making his debut with Carlton.
He played just five AFL games this season, suffering a knee injury in round two and then falling behind novice Reilly O’Brien as the Crows’ preferred ruck.
In July, Adelaide extended O’Brien’s contract until the end of 2021 which prompted Jacobs to explore his options.
The Giants are understood to have offered Jacobs a two-year contract, while his former club Carlton is also believed to have shown interest.
In an Adelaide Football Club statement released this afternoon, Jacobs said it was an “extremely difficult” decision to leave, but but had been made in the best interests of his family.
“It was always a childhood dream to play for the Adelaide Crows and to make that a reality is an achievement I will always be proud of,” he said.
“We didn’t achieve the ultimate success but the relationships and friendships I have made will last a lifetime.
“After a couple of weeks of really open discussions with the Club, I have decided it would be best for my family and career to exercise my free agent options.
“I do this with a heavy heart as I love the Club, it was an extremely difficult decision to make.”
Crows General Manager of List Management and Strategy Justin Reid paid tribute to Jacobs’ ruck craft, durability and team-first approach.
“Sam has carried our ruck duties for a number of years and his ability to play big minutes and perform to a high level has made him one of the League’s most consistent big men over the past decade,” Reid said.
“He is not only a talented footballer but a quality individual who has always been a popular team mate, as well as a fan favourite since the day he arrived.
“Sam shows a genuine care for others and he will always be part of the Crows family, and we wish him, Izzy and Imogen the very best for their next adventure.”
The AFL’s free agency period commences on Friday, October 4.
Jacobs’ depature comes a week after coach Don Pyke announced he was leaving, despite being contracted to 2021.
He resigned after the Crows failed to make the finals for the second consecutive year, after losing the 2017 Grand Final.
The club is currently undergoing an external review into its performance.
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