Six young cats from different households in the United Kingdom were diagnosed with Mycobacterium bovis infection, a member of the Mycobacterium tuberculosis complex. All were indoor-only cats and consumed the same commercial frozen raw feline diet. Seven subclinical in-contact cats from the affected households also had evidence of M bovis infection. Cats were presented with clinical signs including fever, inappetence, and severe weight loss and with diagnostic findings including pyogranulomatous lesions, abdominal mass, lymphadenopathy, and/or pneumonitis. Mortality rate was 83%. M bovis infection is zoonotic; commercial raw meat-based diets pose a significant risk for transmitting infectious pathogens such as M bovis to animals and their owners.