In the gritty Northside of Dublin, Jimmy Rabbitte, an enterprising young music enthusiast, dreams of forming the greatest soul band his city has ever seen. Inspired by the sounds of James Brown, Otis Redding, and Aretha Franklin, he sets out to recruit a crew of talented but inexperienced locals with the hopes of bringing authentic American soul music to the Irish working class. Jimmy places an ad in the local paper and holds auditions in his parents' cramped living room, where a motley parade of musicians and singers showcase their abilities, each bringing their own quirks and ambitions to the mix.

After assembling a diverse band that includes the brash trumpet-playing Joey "The Lips" Fagan, the soulful lead singer Deco Cuffe, and backup singers with both attitude and voices, The Commitments is born. The group endures rigorous rehearsals, leading to frayed tempers and occasional clashes as they try to shape their raw talent into a cohesive sound. As they begin to perform around Dublin, the band starts gaining a passionate following, providing a glimmer of hope that the dream of bringing soul to the people of Dublin might actually become a reality. However, the combustible mixture of egos, unrequited love, and financial pressures loom over their rise, challenging the unity and dedication of The Commitments.