Stefani Joanne Angelina Germanotta (born March 28, 1986), known professionally as Lady Gaga, is an American singer, songwriter, and actress. She is known for her unconventionality and provocative work, as well as visual experimentation. Gaga began performing as a teenager, singing at open mic nights and acting in school plays. She studied at Collaborative Arts Project 21, through New York University's Tisch School of the Arts, before dropping out to pursue a music career. After Def Jam Recordings canceled her contract, Gaga worked as a songwriter for Sony/ATV Music Publishing, where Akon helped her sign a joint deal with Interscope Records and his own label KonLive Distribution in 2007. She rose to prominence the following year with her debut album, the electropop record The Fame, and its chart-topping singles "Just Dance" and "Poker Face". A follow-up EP, The Fame Monster (2009), featuring the singles "Bad Romance", "Telephone", and "Alejandro", also proved successful.
Gaga's second full-length album Born This Way (2011) explored electronic rock and techno-pop. The album peaked atop the US Billboard 200 and sold more than one million copies in the country during its first week. Its title track became the fastest selling song on the iTunes Store with over a million downloads in less than a week. Gaga experimented with EDM on her third studio album Artpop (2013), which reached number one in the US and included the single "Applause". Her collaborative jazz album with Tony Bennett, titled Cheek to Cheek (2014), and her soft rock-influenced fifth studio album, Joanne (2016), also topped the US charts. During this period, Gaga ventured into acting, playing leading roles in the miniseries American Horror Story: Hotel (2015–2016), for which she received a Golden Globe Award, and the critically acclaimed musical romantic drama A Star Is Born (2018). She also contributed to the latter's soundtrack, which made her the only woman to achieve five US number one albums in the 2010s. Its lead single "Shallow" earned Gaga a Golden Globe Award for Best Original Song.
Having sold 27 million albums and 146 million singles as of January 2016, Gaga is one of the best-selling music artists in history. Her achievements include several Guinness World Records, six Grammys, three Brit Awards, and an award from the Songwriters Hall of Fame and the Council of Fashion Designers of America. Gaga has been declared Billboard's Artist of the Year and included among Forbes's power and earnings rankings. She was ranked at number four on VH1's Greatest Women in Music in 2012, finished second on Time's 2011 readers' poll of the most influential people of the past ten years, and was named Billboard's Woman of the Year in 2015. She is known for her philanthropy and social activism, including LGBT rights, and for her non-profit organization, the Born This Way Foundation, which focuses on promoting youth empowerment and combating bullying.