Alexandra Boyd was born to a Scottish father, David Boyd, and an English mother, Barbara Boyd (née Godbold) in Bangor, Wales. She grew up in Norwich, Norfolk, and was educated at Norwich High School for Girls. She left school at 16 to study full-time at Laine Theatre Arts in Epsom, Surrey. In 1986, she enrolled in the post graduate acting course at Drama Studio, London. She co-founded a theatre company that performed Shakespeare and adapted classics for the London and Edinburgh Fringe. The company also produced English plays for Italy. In the 1993 Italian tour, she played Eliza Doolittle in Pygmalion.
