Joanne Dawn Coburn was born on 12 November 1967 in Hendon, London, England. She is Jewish and is an active member of Ealing Liberal Synagogue. Details about her parents and family background are not publicly available.

Coburn worked for local radio stations in Berkshire, Buckinghamshire and Oxfordshire, including Mix 96 Aylesbury, Fox FM Oxford, and Star FM in Slough, before joining BBC London as a regional correspondent for four years. She joined BBC Breakfast in 2001 as a political correspondent, coming to prominence when she covered the 2000 London Mayoral election, and went on to cover the 2001 general election.

In 2008, she joined BBC Two’s weekday political programme Daily Politics, presenting alongside Andrew Neil. Both Politics Europe and Daily Politics were axed in 2018, with the latter replaced by Politics Live, which Coburn presented, alongside the continuing Sunday Politics London.

On 5 June 2025, Times Radio announced that Coburn would be joining it as a presenter. Her first programme was The Times at One on 16 June 2025. She is married to former Downing Street head of strategic communications Mark Flanagan. They have two sons and live in West London.