Tetradactylus fitzsimonsi, commonly known as Fitzsimons' long-tailed seps and FitzSimons' whip lizard, is a species of lizard in the family Gerrhosauridae.

[2] The specific name, fitzsimonsi, is in honour of Irish-born South African herpetologist Frederick William FitzSimons.

[3] The preferred natural habitats of T. fitzsimonsi are grassland and shrubland.

A clutch of 2–5 eggs is laid in a live ant nest (Anochetus faurei).

Each hatchling has a total length (including tail) of about 12.5 cm (4.9 in).