Stefani Joanne Angelina Germanotta (/ˈstɛfəniː dʒərməˈnɒtə/ ste-fə-nee jər-mə-not-ə; born March 28, 1986), known by her stage name Lady Gaga, is an American singer-songwriter, record producer, activist, businesswoman, fashion designer and actress. Born and raised in New York City, she primarily studied at the Convent of the Sacred Heart and briefly attended New York University's Tisch School of the Arts before withdrawing to focus on her musical career. She soon began performing in the rock music scene of Manhattan's Lower East Side. By the end of 2007, record executive and producer Vincent Herbert signed her to his label Streamline Records, an imprint of Interscope Records. Initially working as a songwriter at Interscope Records, her vocal abilities captured the attention of recording artist Akon, who also signed her to Kon Live Distribution, his own label under Interscope.

In 2008, Lady Gaga came to prominence with her debut studio album The Fame, which was a critical and commercial success. The record included the international number-one tracks "Just Dance" and "Poker Face". In 2009, her extended play The Fame Monster was released to a similar reception, and produced the hit singles "Bad Romance", "Telephone", and "Alejandro". Its accompanying Monster Ball Tour became one of the highest-grossing concert tours of all time. Lady Gaga's second album Born This Way (2011) topped albums charts in most major markets and generated chart-topping songs "Born This Way", "Judas", and "The Edge of Glory". Her third album Artpop is planned for release in 2013.

Influenced by David Bowie, Michael Jackson, Madonna, and Queen, Lady Gaga is recognized for her flamboyant, diverse and outré contributions to the music industry through her fashion, performances and music videos. As of October 2011, she had sold an estimated 23 million albums and 64 million singles worldwide and her singles are some of the best-selling worldwide. Her achievements include five Grammy Awards and 13 MTV Video Music Awards. Lady Gaga has consecutively appeared on Billboard magazine's Artists of the Year (scoring the definitive title in 2010), ranked fourth in VH1's list of 100 Greatest Women in Music, is the fourth best selling digital singles artist in US according to RIAA, is regularly placed on lists composed by Forbes magazine, including The World's 100 Most Powerful Women from 2010 to 2013, and was named one of the most influential people in the world by Time magazine. Besides her musical career, she involves herself with humanitarian causes and LGBT activism.