[citation needed] She was born shortly before Cyclone Tracy destroyed the city after which she and her mother were evacuated to Brisbane on December 29, 1974 en route to Townsville.

[2] Johnston-Hollitt attended the University of Adelaide,[3] where she earned two degrees: one in theoretical and experimental physics and the other in mathematics and computer science.

[8][9] Johnston-Hollitt worked on NZ's engagement with the Square Kilometre Array, and she served in an advisory role for the New Zealand Government on the project from April 2009 to January 2018.

[13][14] Johnston-Hollitt led the 2011 bid for NZ to join the Murchison Widefield Array, a low frequency precursor to the SKA.

Johnston-Hollitt's primary research interests are cosmic magnetism and observations of galaxy clusters, primarily through the use of radio telescopes.

[21] Johnston-Hollitt has gained funding for design, construction and exploitation of radio telescopes across Europe, Australia and New Zealand.