Recently reported links between rhythm and grammar processing have opened new perspectives for using rhythm in clinical interventions for children with developmental language disorder (DLD). Previous research using the rhythmic priming paradigm has shown improved performance on language tasks after regular rhythmic primes compared to control conditions. However, this research has been limited to effects of rhythmic priming on grammaticality judgments. The current study investigated whether regular rhythmic primes could also benefit sentence repetition, a task requiring proficiency in complex syntax—an area of difficultly for children with DLD. Regular rhythmic primes improved sentence repetition performance compared to irregular rhythmic primes in children with DLD and with typical development—an effect that did not occur with a non-linguistic control task. These findings suggest processing overlap for musical rhythm and linguistic syntax, with implications for the use of rhythmic stimulation for treatment of children with DLD in clinical research and practice.