Isabella Plains is a suburb in the Canberra, Australia district of Tuggeranong. The postcode is 2905. The suburb is indirectly named after Isabella Maria Brisbane (1821–1849), who was the daughter of Sir Thomas Brisbane, the colonial Governor of New South Wales when the area was first explored by white settlers in 1823. Joseph Wild was employed by Brigade Major John Ovens and Captain Mark Currie to guide them to the Murrumbidgee River. They travelled south along the river and named the area now known as Tuggeranong "Isabella's Plain". This name was adopted, with a slight change of spelling, for the name of the new suburb. It was gazetted on 5 August 1975. Streets are named after New South Wales parish names.
It is next to the suburbs of Monash, Bonython, Richardson and Calwell. It is bounded by Isabella Drive, Drakeford Drive, Johnson Drive and Ashley Drive. Located in the suburb are a small group of shops, the senior campus of St Mary MacKillop College, Isabella Plains Primary School, the Tuggeranong automatic weather station and Isabella Plains neighbourhood oval.