Kacey began her professional career in the award winning musical Annie at the Victoria Palace in 1978 having been selected from a large open audition. She returned for two subsequent runs of Annie after which she made appearances on Saturday morning television, a few musicals and a film with Peter Sellers. She ‘retired’ from acting aged 14 to concentrate in her education but joined the Cockpit Youth Theatre and the Young Vic Youth Theatre for fun. After completing her education, she auditioned for Central School of Speech and Drama graduating in 1994 with a BA in Acting. After Central she completed a season at Harrogate rep appearing in The Merchant of Venice and The Boys From Syracuse. Kacey then worked in several young writers’ and new writers’ workshops at the Royal Court, Soho Theatre and Paines Plough before being cast as Lucy in award winning playwright Joe Penhall’s Pale Horse with Ray Winstone at the Royal Court, followed by Serving it Up (Bush), Attempts on her Life (Royal Court) and playing Katherine in The Taming of the Shrew for the English Touring Theatre. In between her theatre work she appeared in A Touch of Frost, (ITV) Peak Practise III (ITV) Soldier, Soldier V (ITV), two Screen One productions for the BBC, The Beggar Bride and The Moonstone, Touch and Go (C4) and two series of The Cone Zone (CITV). Films include: The Sin Of Gluttony (C4) That Lady From Rio with Hugh Laurie and Mike Leigh’s Oscar winning movie Topsy Turvey as well as shorts Ticks (Dragon films) and Hip Hip Hooray and several radio plays.
In 2000 she began an 8 week improvisational process to find a new family for Eastenders ultimately creating the role of Little Mo Slater. She stayed in Eastenders for six years winning every major best actress award including an NTA for best actress and accepting the television BAFTA for best continuing drama series in 2003 on behalf of Eastenders.
Kacey left Eastenders to head a new series for the BBC, Holby Blue appearing in two series before leaving to bring up her two children and build her own Eco house.
Kacey returned to acting appearing in Calendar Girls (David Pugh), Carries War (Apollo West end) , Steel Magnolias (David Ian productions), Laughton (Stephen Joseph Theatre), Feed The Beast (Birmingham Rep) and on television as guest leads on Casualty (BBC) Midsommer Murders (ITV), Doctors (BBC) and Call the Midwife Christmas Special (BBC) she is currently filming the second series of Grantchester (ITV) playing series regular Cathy Keating alongside Robson Green and James Norton.