[1][2] O'Flynn, currently stars in Everyone Else Burns (2023–present) and has had recurring roles in Landscapers (2021) and My Lady Jane (2024) as well as appearing in the films Happy-Go-Lucky (2008) and Bridget Jones' Baby (2018).
In the same year, O'Flynn appeared with Russell Tovey at London's Royal Court Theatre in Molly Davies' A Miracle.
[7] In the Evening Standard, Nicholas de Jongh praised O'Flynn's "beautiful rendering of passivity, selfishness and vulnerability",[8] while The Daily Telegraph's Charles Spencer wrote, "Kate O'Flynn brings an astonishingly raw vulnerability to the stage as Amy, the tears streaming down her face as she describes how impossible she finds it to love and nurture her child".
[11] In 2012, O'Flynn played the role of Beryl in BBC Four's BAFTA Award-winning[12] television adaptation Room at the Top, based on John Braine's novel of the same name.
Writing in The Guardian, Maddy Costa noted: "As Rachael [sic] in Simon Stephens's Port, she grew from a mouthy 11-year-old to a downtrodden but resilient 24-year-old – and in the process transformed from a relative unknown to a star in the making".
In 2015 O'Flynn played the part of Dr Peep in police comedy drama No Offence,[16] reprising her role in all three series.
[17] In the same year, she also played Lady Alexandrina De Courcy in the ITV costume drama Doctor Thorne, based on Anthony Trollope's novel of the same name.