Tonnicinctus is an extinct species of pampatheriid that lived in Argentina during the Pleistocene and Holocene.

Tonnicinctus inhabited cool grassland regions. It was a medium-sized pampatheriid, smaller than its better-known relatives like Pampatherium and Holmesina. It is distinguishes from other Pampathreres by: osteoderms which are intermediate in thickness between Pampatherium and Holmesina; very wide anterior and lateral margins with several large and deep foramina; wide and uniform marginal elevation in the fixed osteoderms and very narrow marginal elevation in movable and semi-movable osteoderms of the scapular and pelvic buckler.