Nicky Cadden is joining twin brother Chris at Hibernian after agreeing a three-year deal at Easter Road.
The 27-year-old left winger arrives as a free agent after two seasons at Barnsley.
He began his career at Airdrieonians, moving on to Livingston, Morton and Forrest Green Rovers before his switch to Oakwell in 2022.
"Nicky is a player I have always admired," said head coach David Gray. "He brings great quality, consistency and is a top professional.
"He knows the Scottish game. He has a great delivery into the box and has contributed goals and assists everywhere he has been. I am confident he will slot nicely into the dressing room straight away."
Sporting director Malky Mackay described Hibs' seventh summer signing as an "extremely versatile player", explaining that he offers "different options across the midfield and at left-back as well."
Chris Cadden, who plays on the right, has been at Hibs since 2021.