In 1999, she co-wrote and starred in Spaced. Her London theatre début was in April 2002, playing the tough ex-prisoner "Bolla" in Jez Butterworth's The Night Heron at the Royal Court. In 2004 she played a minor part as Yvonne in horror comedy Shaun of the Dead, again working with Pegg and Wright. In the same year she was also cast as Magda, friend of the titular character, in the Hollywood sequel Bridget Jones' Diary 2 also called Bridget Jones' Diary: The Edge of Reason. In 2005 Hynes took the lead role in the BBC One sitcom According to Bex (which she thought was so bad that she sacked her agent for putting her up for it), and had a starring role in British comedy Confetti alongside Jimmy Carr, Martin Freeman and Mark Heap.