Cartmell began his career with spells at Huddersfield Town, Blackpool, Mardy and Abertillery before the outbreak of the First World War in 1914 saw the suspension of competitive football the following year. Cartmell guested for Heart of Midlothian during the war, making 19 appearances during the 1916–17 season.
After the armistice, Cartmell joined Southern League Division One side Brentford in 1919. He made 30 appearances during the Bees' first season of league football in 1920–21, before leaving at the end of the campaign.
Cartmell returned to Brentford in 1926, when he followed manager Harry Curtis, trainer Bob Kane and a number of former Gillingham players to Griffin Park. He progressed to become the club's lead trainer and remained with the Bees until the mid-1950s. Cartmell was rewarded for his long service with a testimonial match against Hayes in April 1955.