List of Famous people named Sian

Sian Proctor is an American geology professor, science communicator, and commercial astronaut. She was selected as the pilot for the Inspiration4 private orbital spaceflight conducted on 15th September 2021, aboard a SpaceX-operated Crew Dragon space capsule. She is a geology professor at South Mountain Community College in Arizona. She is also a major in the Civil Air Patrol where she serves as the aerospace education officer for its Arizona Wing.

Dame Jane Elizabeth Ailwên Phillips,, known professionally as Siân Phillips, is a Welsh actress. She has performed the title roles in Ibsen's Hedda Gabler and G. B. Shaw's Saint Joan.

Siân Gibson is a Welsh stand-up comic, actor, impressionist and writer. She has collaborated with Peter Kay, including starring in and co-writing the comedy series Peter Kay's Car Share, for which she won the 2016 BAFTA TV Award for Best Scripted Comedy and the National Television Award for Best Comedy.

Sian Brooke is a British actress, known for portraying Eurus Holmes in Sherlock.

Siân Mary Lloyd is a Welsh television presenter and meteorologist from Maesteg. She is the United Kingdom's longest-serving female weather forecaster, having appeared on ITV Weather for 24 years, from 1990 until 2014.

Sian Clifford is an English actress. She is best known for playing Claire, the older sister of the titular character in the BBC comedy-drama series Fleabag (2016–2019) and also portrayed Martha Crawley in the ITV/Amazon Studios series Vanity Fair (2018). In 2020, she played Diana Ingram in the ITV series Quiz.

Sian Louise Massey-Ellis, is an English football match official who officiates generally in the role of assistant referee in the Premier League and the Football League. She has also been appointed to matches in the Football League Trophy, UEFA Women's Champions League, FIFA Women's World Cup qualification rounds, the FIFA Women's World Cup and the UEFA Europa League. Massey-Ellis turned professional in 2010 and was appointed to the FIFA list of women assistant referees in 2009.

Siân Rebecca Berry is a British politician who has served as Co-Leader of the Green Party of England and Wales alongside Jonathan Bartley since 2018. From 2006 to 2007, she was one of the Green Party's principal speakers.

Siân Catherine James is a Welsh Labour Party politician, who was Member of Parliament (MP) for Swansea East from 2005 to 2015.

Siân Thomas is a British actress who trained at the Central School of Speech and Drama. She is known both for her work on stage and for her television and film appearances such as Harry Potter and the Order of the Phoenix in which she played Amelia Bones. Her voice is known to listeners both for her poetry readings on Radio 3 and for her audiobooks.