Stefanie Fabienne Heinzmann (born 10 March 1989) is a Swiss pop singer and television personality. She gained public interest in early 2008 when she won SSDSDSSWEMUGABRTLAD, a talent contest hosted in Stefan Raab's late-night-show TV total on the German ProSieben network. Following her win, Heinzmann released her debut single "My Man Is a Mean Man," which debuted straight atop the Swiss Singles Chart and became a top ten hit in Austria and Germany. Her pop soul-influenced album Masterplan was released in March 2008 and made it to the top ten in Austria and Germany, also reaching number one in Switzerland, where it was certified platinum by the IFPI for more than 30,000 copies sold.

Heinzmann followed this with a series of successful albums, including the chart toppers Roots to Grow (2009), Stefanie Heinzmann (2012), Chance of Rain (2015) and All We Need Is Love (2019), all of which entered the top five in Switzerland. Several singles from these albums became top ten hits on the pop charts throughout German-speaking Europe, including "The Unforgiven", "Diggin' in the Dirt", and "In the End". One of the best-selling Swiss artists to emerge in the late 2000s, Heinzmann has won several high-profile prizes as a recording artist such as Prix Walo, the 1LIVE Krone, a Comet, a Swiss Music Award, the Radio Regenbogen Award, and the 2009 ECHO Award. Beyond her music career, Heinzmann has been featured as a coach on two seasons of the reality competition television series The Voice of Switzerland, the talent series Popstars, the music game show The Masked Singer, and Sing meinen Song – Das Schweizer Tauschkonzert.