Brentford have signed Bologna defender Aaron Hickey for £17m including add-ons.
The 20-year-old Scotland international has signed a four-year deal and joins the Bees subject to international clearance.
Hickey moved to the Serie A club from Heart of Midlothian in 2020 and made 36 appearances last season, scoring five goals and registering one assist.
“I am very pleased to sign Aaron,” Brentford boss Thomas Frank said.
“What he has already achieved in his career is very impressive. He is only 20 and has played a full season in Scotland as well as almost two seasons in Serie A.”
Hearts are due a cut of the transfer fee from a sell-on clause in his contract.
Hickey will provide competition for current first choice left-back Rico Henry at the Community Stadium.
“We think that Aaron is a player with great potential, who already has an impressive number of games at a good level under his belt,” Frank added.
“We believe that we have proven we are a good club for players to maximise their potential. We think we can help him be even better.
“Aaron is a rare thing in modern football in that he is equally good with both feet. He is technically very sound and is good when he has the ball in tight areas. He is an attacking full-back that has good creativity, he is a great crosser of the ball and scored goals in Serie A last year.
“Having played two years in Italy, we know he will have good defensive traits. There are areas to improve and we are looking forward to having him with us so we can be part of his development as a player.”