28 January 1983
Roath, Cardiff, Wales
Lark was born in Roath, Cardiff to Bev and Billy Lark, and began performing at an early age. When she was twelve years old she played the lead role in the Starstruck Theatre production of musical, Annie at St Peter's Church Hall in Roath alongside Charlotte Church, who took the role of Molly. She appeared in the television series The Biz and The Healer and appeared in the original performance of the Andrew Lloyd Webber musical, Whistle Down The Wind at the Sydmonton Festival held at Lloyd Webber's country house, Sydmonton Court in 1995 as part of the ensemble.
In 2000 Lark made her West End debut creating the role of "Little Girl" in Cameron Mackintosh's production of The Witches of Eastwick at the Theatre Royal, Drury Lane. In 2003 she played John Barrowman's daughter in the musical, Beautiful and Damned at the Yvonne Arnaud Theatre in Guildford, Surrey.
After appearing as Lucy in a production of Snoopy!!! The Musical at the Jermyn Street Theatre in 2003, Lark undertook a Post-Graduate course in Musical theatre at the Royal Academy of Music. Here in 2004 she played the roles of Julie in Victoria Wood's play Talent and also Hermia in A Midsummer Night's Dream. She graduated with a distinction and then went on to reprise her role in Snoopy!!! at The New Players' Theatre in 2004. In 2005 she joined the musical Mamma Mia! at the Prince of Wales Theatre, as cover for the roles of Lisa and Sophie.
She stayed in Mamma Mia! for two years before making her first appearance at the Edinburgh Fringe Festival in 2007, performing in C Theatre's productions of Cinderella, in the title role and the annual Shakespeare For Breakfast, as Juliet's nurse. The latter making a successful transfer to the Canal Cafe Theatre in Little Venice, London.
I'd Do Anything
Lark was a finalist on I'd Do Anything on BBC One from March to May 2008, a show which searched for a new, unknown lead to play Nancy in a West End revival of the British musical Oliver!. She was eliminated in show six on 4 May.
Immediately after the show Lark participated in the I'd Do Anything tours with fellow contestants Ashley Russell, Keisha Amponsa-Banson and Niamh Perry, along with Michael French and Connie Fisher, accompanied by the BBC Singers and the BBC Symphony Orchestra.
After participating in a workshop production at the Menier Chocolate Factory in the London Borough of Southwark, Lark performed as Collette in Conor Mitchell's Mathilde at the 2008 Edinburgh Comedy Festival, directed by Simon Callow. In September 2008 she performed as the lead female vocalist in the show Hit's of the West End at the Hamilton Townhouse, Hamilton, South Lanarkshire.
 On 14 October she appeared in a one-off charity performance of the musical comedy Betwixt! at the Ambassadors Theatre in Covent Garden, London. On 9 November 2008 she performed a solo cabaret act An afternoon with Sarah Lark, at Lauderdale House in Waterlow Park, Highgate in north London.
In February 2009, Lark performed at the 2009 Whatsonstage Theatregoers' Choice Award at the Prince of Wales Theatre in London. She sang "9 to 5" with fellow I'd do Anything contestant Samantha Barks and X-Factor finalist Niki Evans, then the title track from the Broadway musical Xanadu.
In November 2009, Lark performed at an all-star concert celebrating the work of young British composer Michael Bruce at the Apollo Theatre. Other performers to feature in the concert included West End Stars Julie Atherton, Paul Spicer and Leanne Jones, Eurovision: Your Country Needs You finalist Mark Evans, Any Dream Will Do finalist Daniel Boys, and How Do You Solve A Problem Like Maria? finalist Helena Blackman.
After appearing on I'd do Anything Lark's next major show was as the Strawberry seller in Cameron Mackintosh's revival production of Oliver! at the Theatre Royal, Drury Lane, London. She understudied the part of Nancy, performing it on a few occasions during the absence of winner Jodie Prenger, performing opposite Rowan Atkinson, Omid Djalili and Griff Rhys Jones as Fagin, and Burn Gorman and Steven Hartley as Bill Sykes. Lark departed the cast on 27 March 2010 after performing in the production for 14 months.
The Best Little Whorehouse in Texas
What the World Needs Now - The Music of Burt Bacharach
In February 2012 Lark appeared as a special guest vocalist at a Valentine's Day concert of the music of Burt Bacharach, alongside Cat Simmons and the Royal Philharmonic Orchestra. The concert programme was recorded as an album with the RPO and performed several more times around the UK, including a special performance with the BBC Concert Orchestra for BBC Radio 2's Friday Night is Music Night broadcast live from the Mermaid Theatre in London, presented by Paul Gambaccini.
- The Witches of Eastwick – Original cast recording, as Little Girl (2000).
- Oliver! – Live cast recording, as Strawberry Seller (2009).
- Bluebird  – Original concept cast recording, as Roberta (2009).
- "Nancy Contestants – Sarah". bbc.co.uk. 6 February 2008. Retrieved 9 May 2008.
- "Nancy Contestants – Sarah". Media Wales Ltd. 26 March 2008. Retrieved 10 October 2008.
- "Sarah Lark". The Spotlight. Retrieved 10 October 2008.
- Matthewman, Scott (25 March 2008). "I'd Do Anything: Meet the Nancies". The Stage. Retrieved 11 September 2008.
- "Witches of Eastwick". About Maria – The Maria Freedman website. Retrieved 21 August 2008.
- "Mathilde by Conor Mitchell". Edinburgh Comedy Festival. Retrieved 24 August 2008.[dead link]
- Brown, Lesley. "West End comes to town in autumn". Hamilton Advertiser. Retrieved 24 August 2008.
- Shenton, Mark (30 October 2008). "Carroll and Lark Join Company of London Oliver! Revival; Casting Now Complete". Playbill. Retrieved 31 October 2008.
- "Actresses". Cole Kitchenn. Retrieved 5 October 2008.
- "Cabaret in the House – Sarah Lark". The Stage. 9 November 2008. Retrieved 11 November 2008.
- "2009 Whatsonstage.com Theatregoers' Choice Awards Concert". Whatsonstage Theatregoers' Choice Award. Retrieved 13 March 2009.
- . WhatsOnStage http://www.whatsonstage.com/news/theatre/london/E8831251737944/All-Star+Concerts+of+Michael+Bruce+%26+Lance+Horne.html. Retrieved 28 May 2014. Missing or empty
- Paul Vale (5 December 2011). "The Stage – Reviews – Snow White and the Seven Dwarfs". Thestage.co.uk. Retrieved 28 May 2014.
- "Sue Holderness and S Club 7's Tina Barrett look forward to Chatham's pantos at the Central Theatre and the Britannia Theatre". Kent Online. Retrieved 12 January 2017.
- "The Music of Burt Bacharach at Cadogan Hall". Cadoganhall.com. 14 February 2012. Retrieved 28 May 2014.
- "Concert Diary". GRB Concerts. Retrieved 12 January 2017.
- "Friday Night is Music Night". BBC. BBC. Retrieved 12 January 2017.
- . londonmusicalsONLINE http://www.londonmusicalsonline.com/production.php?ProdID=LM. Retrieved 28 May 2014. Missing or empty
-  Archived 5 October 2012 at the Wayback Machine.