William James Adams Jr. (born March 15, 1975), known professionally as will.i.am (pronounced "will I am"), is an American rapper, singer, songwriter, record producer, actor, and entrepreneur. He is the frontman of the musical group Black Eyed Peas, which he formed with fellow musicians apl.de.ap and Taboo in 1995. The group, having released nine total studio albums, saw their furthest mainstream success during their 2000s pop rap era with Elephunk (2003), Monkey Business (2005), The E.N.D. (2009), and The Beginning (2010). Adams served as lead vocalist since its formation, although for the albums, he did so alongside singer Fergie—who joined the group in 2002 and departed after the latter.

As a solo artist, Adams released his first two albums, Lost Change (2001) and Must B 21 (2003) to lukewarm commercial response. The former was released by Atlantic Records, while the latter contained the song "Go!", which served as theme music for the NBA Live 2005 and Madden NFL 2005 seasons. His third album, Songs About Girls (2007) marked his first entry on the Billboard 200 as a solo act and spawned the moderate hit single "I Got It From My Mama." His fourth album, #willpower (2013) peaked at number nine on the chart and saw further success with its singles "Scream & Shout" (with Britney Spears) and "#thatPOWER" (featuring Justin Bieber). The former song peaked at number three on the Billboard Hot 100. In addition, his guest appearances on Fergie's 2006 single "Fergalicious" and Usher's 2010 single "OMG" peaked at numbers two and one on the chart, respectively. In 2024, he confirmed his untitled fifth studio album will be released that year.

A prolific record producer and songwriter, Adams has amassed credits on singles and albums for other artists including Michael Jackson, Rihanna, Miley Cyrus, Kanye West, Jennifer Hudson, U2, Kesha, Lady Gaga, Psy, Justin Timberlake, Nicki Minaj, Estelle, Nas, John Legend, Cheryl, and 2NE1, among others. Through his solo career and collaborative work with the Black Eyed Peas, he has a total of 41 top-40 entries on the UK Singles Chart since 1998, and has sold 9.4 million singles in the country. He founded his namesake record label in 1998, which has signed artists including LMFAO, Kelis, and Macy Gray.

Outside of his music, Adams has served as a panelist and mentor on the reality competition series The Voice UK (2012–present), The Voice Australia (2014), and The Voice Kids (2017–2023). He is the recipient of seven Grammy Awards, a Latin Grammy Award, and a Daytime Emmy Award.