Karl Amon has become the first player to move clubs during the AFL trade period, leaving Port Adelaide to join Hawthorn on a four-year deal.
The 27-year-old wingman has played 124 games for the Power over the last nine seasons.
He was Port Adelaide's top vote-winner in this year's Brownlow Medal, averaging 23.6 disposals a game throughout the season.
"We are thrilled to officially welcome Karl to Hawthorn," Hawks list manager Mark McKenzie said in a statement.
"It's pleasing to hear Karl indicate his decision to commit to the club was based around the positive direction of the organisation and the exciting brand of football being developed.
"He is an incredibly gifted athlete and can be damaging by foot.
"With more than 100 games under his belt, we believe his skill-set and experience will complement our young and developing list."
The AFL is yet to determine Port Adelaide's compensation for losing the free agent, with the club calling for a first-round draft pick.
"I think it has got to be close to a first round, if not an end of first-round selection," Power football manager Chris Davies told AFL Trade Radio this week.
