Steffy Forrester is a fictional character from the American CBS soap opera The Bold and the Beautiful. Introduced by Bradley Bell, she is currently portrayed by Jacqueline MacInnes Wood. Steffy and her twin sister Phoebe (MacKenzie Mauzy) were born onscreen as the daughters of supercouple Ridge Forrester (Ronn Moss, later Thorsten Kaye) and Taylor Hayes (Hunter Tylo, later Krista Allen) during the episode airing on September 21, 1999. For the character's first five-year period, she appeared as a minor. In 2005, Steffy was rapidly aged to a teenager, and in 2008 she appeared as an adult when Wood took over the role. Wood portrayed the role continuously until 2013, when she decided to leave her regular capacity with the series. Following a series of guest appearances, Wood returned as a series regular in 2015.

Steffy has suffered many losses throughout her life, which according to Wood is the reason for her deep-seated issues and puzzling storylines. Wood has also described the character as a "rich bitch". While characterized as being provocative and strong-willed, Steffy is emotionally starved on the inside due to her father's neglect. The character is known for her relationships with the Spencer men: Bill Spencer, Jr. (Don Diamont), Liam Spencer (Scott Clifton) and Wyatt Spencer (Darin Brooks) as well as animosities towards the Logan family, particularly her mother's rival Brooke Logan (Katherine Kelly Lang) and Steffy's own arch-rival Hope Logan (Kim Matula, later Annika Noelle). For several years, Steffy's storylines revolved around a long-running love triangle with Hope and Liam, before falling in love and entering in a significant relationship with medical doctor, John Finnegan (Tanner Novlan).

Soaps in Depth called Steffy the soap opera genre's "resident diva", while journalist Michael Logan referred to her as a "maddeningly complicated sexbomb". Wood's performance in the role has been met with favorable reception from audiences and critics, having garnered her two consecutive nominations for the Daytime Emmy Award for Outstanding Younger Actress in a Drama Series in 2012 and 2013. In 2018, she received her third Daytime Emmy nomination for Outstanding Supporting Actress in a Drama Series before winning in the Outstanding Lead Actress in a Drama Series category in 2019 and 2021.