Sheridan Caroline Sian Smith OBE (born 25 June 1981) is an English actress, singer and television personality. Smith came to prominence after playing a variety of characters on sitcoms such as The Royle Family (1999–2000), Two Pints of Lager and a Packet of Crisps (2001–2009), Gavin & Stacey (2008–2010), and Benidorm (2009). She played the role of Joey Ross on the drama series Jonathan Creek (2009–2013) and went on to receive acclaim for starring in a succession of television dramas, such as Mrs Biggs (2012), Cilla (2014), The C Word (2015), Black Work (2015), and The Moorside (2017). Her feature film credits include Tower Block (2012), Quartet (2012), and The Huntsman: Winter's War (2016).

Smith has performed in the West End musicals Little Shop of Horrors (2007), Legally Blonde (2010), Funny Girl (2016), and Joseph and the Amazing Technicolour Dreamcoat (2019). She released her debut album, Sheridan, in 2017. Her second album, A Northern Soul, was released in 2018.

In late 2006, Smith started voicing Lucie Miller for Doctor Who, as part of the BBC7 Big Finish audio range, alongside Paul McGann's Eighth Doctor, in the story Blood of the Daleks.

Smith performed at D-Day 75: A Tribute to Heroes commemorating the 75th anniversary of the Normandy landings during World War II. She sang "When the Lights Go On Again" twice, the second time as the closing song.

Smith is the recipient of two Laurence Olivier Awards, a British Academy Television Award, a National Television Award and a BPG Award, as well as two International Emmy Award nominations. She was appointed Officer of the Order of the British Empire (OBE) in the 2015 New Year Honours for services to drama.