The 30-year-old has put pen to paper on a two-year deal with an option for a third, arriving from Bangladeshi outfit Sheikh Russel.
Isma had spells in Scotland in 2013 with the Buddies and 2017 at Tynecastle Park. On either side and between those stints he has had a somewhat nomadic career with France, Portugal, Cyprus, Greece, Saudi Arabia, Uzbekistan, Iran, India, Japan and most recently Bangladesh.
He helped St Mirren win the League Cup in 2013, scoring eight goals in 16 games, while he netted 15 in 42 for Hearts.
Livi boss David Martindale is hopeful he can find that form in his attack next season.
“I’m really happy to get this one over the line," he told the Livingston website. “I was alerted to Esma’s availability a few weeks ago and after some due diligence, I arranged for Esma to fly over and have a look at the club last week.
“I had a very enjoyable chat about football with Esma and knew he would be a good fit for our club. He hasn’t played a lot of football of late but I feel we can afford him that opportunity.
“Esma can play anywhere across the front 3 but was more predominantly used as a number 9 in his previous spells in Scotland.
“He knows the league well and likes the physicality the Scottish league will throw at him and has an eye for a goal.
“I’m confident that Esma, once up-to-speed, will prove to be a valuable member of the first-team squad.”