Mothiba has been on the books of French side Lille for several years but previously enjoyed loan spells at Valenciennes before returning to Les Dogues.
The 22-year-old has since gone on to make a name for himself and commanded a regular place in the Lille squad.
After returning from loan, Mothiba made 14 appearances last season, scoring five goals.
He has since made three appearances for Lille this season, netting once. But he will now hope to continue his rise as he put pen to paper on a five-year deal with Strasbourg.
The striker’s exploits have certainly not gone unnoticed as he was most recently also rewarded with a call-up to Stuart Baxter’s latest Bafana Bafana squad ahead of their all-important 2019 Africa Cup of Nations qualifier against Libya.
Nonetheless, after completing his move with only hours remaining until the July/August transfer window shuts, Mothiba revealed delight following the announcement of his transfer.
"Work hard at training and always give my best,” Mothiba told the club’s website.
“Life is beautiful, I am lucky to be a footballer, so I have to enjoy every moment," he added.
"I am very happy to sign at Racing. I will give everything to the club, work hard every day and try to score a lot of goals to make people happy, he concluded.
It now remains to be seen whether or not Mothiba will feature in time for Strasbourg’s clash with Nantes on Saturday.
The club are currently placed 11th on the Ligue 1 standings, having won just one of their opening three encounters.
🚨 L’attaquant international sud-africain 🇿🇦 @LeboMothiba11 (22 ans, 1,82 m, 78 kg) s’est engagé pour 5 ans en faveur du Racing ! #Bienvenue #Mothiba #Mercato— RC Strasbourg Alsace (@RCSA) August 30, 2018
➡️ https://t.co/1lx8UbQCeP pic.twitter.com/z5ztnSUMnt