Tom Mitchell is set to join the Hawks after the Swans reached an in-principle agreement that Sydney will secure selection 14 in the 2016 AFL Draft.
The out-of-contract midfielder notified the Swans earlier this week of his intention to seek a trade to Hawthorn.
The two clubs have also agreed to swap later draft picks, which will be formalised next week.
Swans head of football Tom Harley says it means Sydney has two first-round draft picks for the first time since 2009.
“Although we are disappointed that Tom has chosen to leave, once he made his intentions clear we were determined to achieve a fair trade for him.
Mitchell was drafted to the Swans in 2011 from Claremont (WA) as the Club’s first round father-son selection (No. 21 overall).
He has played 65 games for Sydney since making his debut in 2013.
The Swans will hold picks 14, 17, 38 and 56 in the upcoming draft once the Mitchell swap goes through.