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) 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.