Stephanie Beacham (born 28 February 1947) is an English actress, businesswoman and former model. In a career spanning almost six decades, she has a wide number of credits to her name on film, television, stage and radio in both the United Kingdom and the United States.

Beacham began appearing on British television in 1967 and made her big screen debut in the 1970 film The Games following this with The Ballad of Tam-Lin (1970) with Ava Gardner, before starring opposite Marlon Brando in the 1971 film The Nightcomers. By the mid-1970s, Beacham had become widely known for her roles in multiple British horror films including Dracula A.D. 1972 (1972), And Now the Screaming Starts! (1973) and House of Mortal Sin (1975), and headlined her own daytime soap opera in Marked Personal (1973–1974), however after garnering acclaim with successful starring roles in the television series Tenko (1981–1982) and Connie (1985), it was Beacham's role as Sable Colby in the ABC series Dynasty (1985–1989) and its spin-off The Colbys (1985–1987) that would make her a household name on both sides of the Atlantic.

Following the cancellation of Dynasty, Beacham starred as the title role in Sister Kate (1989–1990), Iris McKay in the American teen sitcom Beverly Hills, 90210 (1991–1994), Dr. Kristin Westphalen in Steven Spielberg's NBC science fiction series SeaQuest DSV (1993–1994), Countess Regina Bartholomew in Star Trek: The Next Generation (1993) and Dorothea Grant in No Bananas (1996). Beacham's film roles consisted of Troop Beverly Hills (1989), The Wolves of Willoughby Chase (1989), To Be the Best (1991) and Secrets (1992), Relative Values (2000), Love and Other Disasters (2006) and Wild Oats (2016).

Beacham returned to the UK to play Phyl Oswyn in the ITV prison-based drama series Bad Girls (2003–2006), Martha Fraser in the long-running ITV soap opera Coronation Street (2009, 2022), Lorraine in the Sky One sitcom Trollied (2012) and Maureen in the BBC sitcom Boomers (2014–2016), as well as venturing into reality television competing on Strictly Come Dancing (2007) and Celebrity Big Brother (2010).

Beacham has appeared on stage on both the West End and Broadway, with roles including Mrs. Cheveley in An Ideal Husband (1996–2001), Elizabeth I in Elizabeth Rex (2002) and Maria Callas in Master Class (2010–2011). She was nominated for a Golden Globe Award in 1990 for her role in Sister Kate, as well as several other nominations for playing Sable Colby in The Colbys and Dynasty.