Isobel Dorothy "Bel" Powley (born 7 March 1992) is an English actress best known for playing Daisy Miller in the CBBC television series M.I. High. Powley plays the protagonist in the 2015 film The Diary of a Teenage Girl, which premiered at the 2015 Sundance Film Festival.
Powley was born in the Hammersmith district of London, England, to British actor Mark Powley and casting director Janis Jaffa. Her mother is Jewish. Powley attended Holland Park School.
From 2007 until 2008, Powley was one of the lead characters in M.I.High, starring in 23 episodes alongside Rachel Petladwala and Moustafa Chousein-Oglou. In addition to M.I.High, Powley has also appeared in several other productions such as Murderland (three episodes, 2009), Little Dorrit (2008), The Bill (2008) and The Whistleblowers (2007). In 2013, it was announced that Powley was joining the cast of the ITV series Benidorm for series six.