Christina María Aguilera ( AG-il-AIR-ə, Spanish: [kɾisˈtina maˈɾi.a aɣiˈleɾa]; born December 18, 1980) is an American singer, songwriter, actress, and television personality. Recognized as an influential figure in music, she is noted for her four-octave vocal range, use of the whistle register, and incorporating feminism and sexuality into her music. Referred to as the "Voice of a Generation", she was also named a Disney Legend, in recognition for her contributions to The Walt Disney Company.

After appearing on The All-New Mickey Mouse Club (1993–1994) as a child, Aguilera recorded the theme song, "Reflection", for the animated film Mulan (1998) and signed a record deal with RCA Records. She rose to fame in 1999 with her self-titled debut album which gained three number one singles on the US Billboard Hot 100 including "Genie in a Bottle", "What a Girl Wants" and "Come On Over Baby (All I Want Is You)". After winning the Grammy Award for Best New Artist, she followed with Mi Reflejo (2000) and My Kind of Christmas (2000); with the former becoming the best-selling Latin pop album of 2000. Seeking a departure from her teen idol image, Aguilera took on a more provocative image and released Stripped (2002), which went on to become one of the best-selling albums of the 21st century. After another musical reinvention, she released the critically praised Back to Basics (2006). Throughout these periods, she amassed various worldwide hits including the number one single "Lady Marmalade".

During the early 2010s, Aguilera released the albums Bionic (2010) and Lotus (2012) which peaked inside the top ten of the US Billboard 200. She returned to mainstream success with a string of collaborations, including "Feel This Moment", "Say Something", and "Moves like Jagger"; the latter topped the Hot 100, making Aguilera one of the few artists to reach the number one spot over three decades. She found critical success with her follow-up albums Liberation (2018) and Aguilera (2022) and has since performed in two concert residencies. Outside of music, she also starred in the 2010 film Burlesque and contributed to its soundtrack, earning a Golden Globe Award nomination. Her concurrent ventures included a role in the series Nashville (2015), roles in films The Emoji Movie (2017) and Zoe (2018), becoming an ambassador for the World Food Programme (WFP), co-founding the company Playground, and serving as a coach on the reality competition show The Voice (2011–2016).

Aguilera is one of the best-selling music artists of all time, with estimated sales of over 90 million records sold worldwide. As a triple threat entertainer, she has been named one of the greatest vocalists of all time by Rolling Stone and Consequence of Sound and has been hailed as one of the most successful artists to come out of the 2000s. Billboard named her the twentieth most successful artist of the 2000s decade, and was ranked eighth on VH1's list of greatest women in music. She has since been regarded as one of the most influential Latin artists in the entertainment industry, having helped shape the "Latin explosion" in the music industry. Her accolades include five Grammy Awards, two Latin Grammy Awards, six ALMA Awards, two MTV Video Music Awards (VMA), one Billboard Music Award, one Guinness World Record, and a star on the Hollywood Walk of Fame.