Walls spent his early years as an actor, from 1905, mostly in musical comedy, touring the British provinces, North America and Australia and in the West End. He specialised in comic character roles, typically flirtatious middle aged men. In 1922 he went into management in partnership with the comic actor Leslie Henson. They had an early success in the West End with a long-running farce, "Tons of Money", after which Walls commissioned and staged a series of farces at the Aldwych Theatre that ran almost continuously over the next decade. He and his co-star Ralph Lynn were among the most popular British actors of their time.