It is the first time in six years that the entertainment mogul has signed an artist with no affiliation to one of his reality TV shows.
Labrinth - real name Timothy McKenzie - co-wrote, produced and appeared on Tempah's hits 'Pass Out', which reached No.1 in March, and 'Frisky', which was pipped to the top spot this Sunday by the Cowell-produced Shout For England World Cup single.
The 21-year-old from Hackney, East London will release his debut solo single, 'Let The Sunshine', later this summer, with a full album to follow.
He is currently working on new material for Pixie Lott and JLS, with songwriting/production assignments for the likes of Jay-Z, Rihanna and Cheryl Cole lined up.
As part of the deal, Labrinth will also head up his own imprint label, Odd Child/Syco, whose aim will be "to discover and nurture new talent".
Other artists signed to Syco Music include Susan Boyle, Leona Lewis, Alexandra Burke, Westlife and Il Divo.