Back to Basics is the fifth studio album by American recording artist Christina Aguilera, released on August 11, 2006 by RCA Records as a double album. Serving as executive producer, she enlisted collaborators including DJ Premier, Rich Harrison, Rob Lewis, Mark Ronson, and Linda Perry. Recording sessions began in January 2005 and ended in April 2006, taking place at Chalice Recording Studios and Record Plant.

Inspired by her 1920s–1940s idols, including Billie Holiday, Otis Redding, Etta James, and Ella Fitzgerald, Aguilera sought to bring old-school jazz, blues and soul inspirations with a modernized style into Back to Basics. Primarily a pop and R&B record, the first disc blends old-school and modern R&B with hip hop and urban elements with most songs employing horn samples, while the second disc contains all live-recorded tracks (with the exception of "Candyman"). Lyrically, the album is inspired by real-life events Aguilera had experienced, including her marriage with Jordan Bratman in 2005.

To portray a new persona, Aguilera adopted her new alter ego, Baby Jane, and made several changes to her public appearance, inspired by classic Hollywood movie stars. She promoted the album by performing at concerts from mid-2006 to early-2007, including the 2006 MTV Movie Awards and the 2006 MTV Video Music Awards. The album's supporting tour Back to Basics Tour, which visited countries in North America, Asia, Europe, Australia and Middle East, lasted from late-2006 until late-2008. Back to Basic spawned three international singles: "Ain't No Other Man", "Hurt" and "Candyman".

Back to Basics received positive reviews from music critics who complimented its musical diversity from Aguilera's previous albums while there were others who criticized its length. The record received a Grammy Award nomination for Best Pop Vocal Album, and its lead single "Ain't No Other Man" won Best Female Pop Vocal Performance at the 49th Annual Grammy Awards in 2007. In its first week of release, the album debuted atop the US Billboard 200 chart with first-week sales of 346,000 copies. Back to Basics achieved similar success internationally, reaching the top spot in over fifteen countries including Australia, Canada, Germany, Ireland, Switzerland and United Kingdom. The album has sold 1.7 million copies in the US, and 4 million units worldwide as of November 2013.