Gerda Nicolson was born in Hobart, Tasmania, and as a child moved to Geelong in Melbourne where her parents were both involved in reportory theatre.
She initially studied architecture, but decided instead on a performing career, attaining her dramatic training at the St Martins Theatre, before travelling to London where she worked as a draftsperson.
On returning to Australia in 1961, Nicolson joined Melbourne University's Graduate Society and acted in a number of its amateur stage plays.
Nicholson featured in a TV production titled The Proposal and the Bear for ABC TV, although she first reached wider audiences through her regular roles on television serials firstly with Crawford Productions long-running rural series Bellbird as Fiona Davies.
This was her second role in the show — she had already played a minor guest part as a corrupt officer at another prison in earlier episodes.