Dame Ella Orr Campbell (28 October 1910 – 24 July 2003) was a New Zealand botanist.
An expert on bryophytes, she published 130 scientific papers on liverworts, hornworts, orchids, and wetlands.
She became the first woman faculty member of the Massey Agricultural College (now Massey University) in 1945, and in 2003 the herbarium at Massey was renamed the Dame Ella Campbell Herbarium in her honour.
Following her retirement from teaching in 1976, she continued to research and publish for another two decades, finally retiring in 2000 at the age of 90.