She played the regular role of Sharon Lewis in The Box in 1975 before joining the original cast of The Sullivans as Lil Duggan in late 1976.

In July 2011, as part of a rapidly growing internet meme, she read the book Go the Fuck to Sleep to camera in the style she formerly used on Play School.

She immediately offered to record a reading of the book after being sent a copy by the publisher.,[6] Beginning in 2013, she appeared as Elizabeth Bligh in the 1950s-set Australian melodrama A Place to Call Home on the Seven Network, playing the wealthy matriarch of the family.

The film, concerning the relationship between a single mother and a heroin addict, was a modest box-office success in Australia and received generally favourable reviews from critics.

In 2014 she appeared in a critically acclaimed production of The Beauty Queen of Leenane (Dir: Declan Eames) for the Kin Collective at 45 Downstairs.

In 2015 and 2016 Noni performed in a one-woman play, Mother, (Dir: Matt Scholten), written for her by Daniel Keene, on a national tour produced by If Theatre & Regional Arts Victoria.

Mother received two Helpmann Awards nominations for Best Performance by a Female Actor in a Play and Best Regional Touring Production for If Theatre.

Hazlehurst has also been an ambassador for Barnardo's Mother of the Year, and was awarded an Honorary Doctorate of Letters by her alma mater Flinders University in 2007.