Sean Kelly has signed a one-year deal with Livingston.
The 27-year-old defender arrives from Falkirk and goes straight into the squad for the Premier Sports Cup clash with Raith Rovers on Wednesday night.
Kelly started his career with St Mirren before moving to AFC Wimbledon in 2016.
He returned to Scotland with Ross County for the 2017-18 season before moving to the Bairns last season.
Livi manager David Martindale told the club's official website: "I'm very happy to bring Sean into the club. He's a player I know very well and someone I have always felt should be playing in the Premiership.
"Sean was in training with us for a spell last season but both budget-wise and player-wise, I was at my maximum and already had very good cover in the centre-half area.
"I predominantly see Sean as a left centre-half and that's where I see him being most utilised here, albeit, he can cover the left-back area too.
"He will provide us with competition in the defensive area and I feel it's vitally important that we have players who can do a job in a few positions.
"I'm delighted to get Sean on board – a very capable footballer who I know first-hand is a very good character both on and off the park.
"He knows the game inside out and I have no doubt that he'll be a great signing for us.
"Sean has signed an initial one-year contract with incentives leading to a further year."
