The hairy leaves of Mimetes hirtus give rise to the plant's specific name, hirtus meaning hairy or shaggy in Latin. The leaves are simple, shaped lanceolate to broadly so and sessile or stalkless, densely ascending on the stems. Leaf dimensions are from 2,5 cm to 4,5 cm long and from 0,5 cm to 1,8 cm wide. The leaf margins are ciliate. Older leaves become hairless.
The leafy young plant in picture, not yet flowering, was photographed at Kirstenbosch (Manning, 2009; Rebelo, 1995; iNaturalist; https://pza.sanbi.org).