The three-ranked leaves of Hypoxis filiformis are basal, rigid and near thread-like. The specific name, filiformis, is derived from the Latin words filum meaning thread and forma meaning shape, refering to the leaf-shape. Leaf dimensions are from 6 cm to 30 cm long and from 1,5 mm to 3 mm wide.
The blades are deep green, shiny and variably, shallowly u-shaped in cross-section or roundly keeled, the ribs not prominent. Fine hairs are sparsely present, mainly upon the margins (Van Wyk and Malan, 1997; Lowrey and Wright, 1987; iNaturalist).