His success as Dandy made him a sought-after actor and led to subsequent roles with the BBC and ITV, including as Philip in the BBC production of Stewart Love's "The Sugar Cube" (transmitted 21 June 1961) and ultimately his role as Bert Lynch in "Z-Cars" (1962–78). In this police series, set in the fictional Newtown in Lancashire, his character rose from the rank of PC to Inspector over the series run. Ellis appeared in 629 episodes of this series, an all-time record for any actor's appearances in a TV detective/police series. The impact of "Z-Cars" was such that he became a household name in this era.