Adam Mitchel Lambert (born January 29, 1982) is an American singer, songwriter and actor. He is known for his dynamic vocal performances that combine his theatrical training with modern and classic genres. Lambert rose to fame in 2009 after finishing as runner-up on the eighth season of American Idol. Later that year, he released his debut album For Your Entertainment, which debuted at number three on the U.S. Billboard 200. The album spawned several singles, including "Whataya Want from Me", for which he received a Grammy nomination for Best Male Pop Vocal Performance.

In 2012, Lambert released his second studio album Trespassing. The album premiered at number one on the U.S. Billboard 200, making him the first openly gay artist to top the album charts. In 2015, Lambert released his third album The Original High, which debuted at number three on the U.S. Billboard 200 and produced the single "Ghost Town". Since 2009, he has sold over three million albums and five million singles worldwide.

Alongside his solo career, Lambert has performed with Queen in several worldwide tours from 2012. Their first album, Live Around the World, was released in October 2020, and debuted at number one on the UK Albums Chart.

In late 2019, Lambert founded the non-profit Feel Something Foundation, anchoring his ongoing philanthropy, LGBTQ+ and human rights activism. Its particular focus is support for organizations and projects that directly and disproportionately impact the LGBTQ+ community, including education and the arts, mental health, suicide prevention and homelessness.

Lambert made his Broadway debut in 2024, replacing Eddie Redmayne as the Emcee in the revival of Cabaret on September 16.

Lambert was born in Indianapolis, Indiana, on January 29, 1982, to mother Leila, a dental hygienist; and father Eber Lambert, a program manager for Novatel Wireless. His father is of partial Norwegian descent and his mother is Jewish, with Romanian-Jewish roots. Lambert was raised in his mother's religion. He has a younger brother, Neil. Shortly after his birth, his family moved to San Diego, California.

Lambert began performing with Metropolitan Educational Theatre network (now MET2) from the age of nine. A few years later, he began more intense acting and vocal coaching, continuing to perform with both MET2 and what was to become the Broadway Bound Youth Theatre Foundation, as he moved through Mesa Verde Middle School and then Mount Carmel High School. There, he became heavily involved with theater and choir, performed vocals with the school's jazz band, and competed in the local Air Bands competitions. He also appeared in local professional productions such as Hello, Dolly!, Camelot, The Music Man, Grease, Chess and Peter Pan, at venues such as The Starlight, The Lyceum and others.

After graduating from high school in 2000, he attended California State University, Fullerton. His major was musical theater, but he withdrew from the program after five weeks to move to Los Angeles: "I just decided that what I really wanted to do was try to work in the real entertainment world. Life is all about taking risks to get what you want."