Bad is the seventh studio album by American singer-songwriter Michael Jackson. It was released on August 31, 1987, by Epic Records. The album was highly anticipated, taking three years to produce between 1985 and 1987, and was Jackson's third and final collaboration with producer Quincy Jones. Jackson adopted a more aggressive sound and incorporated new digital synthesizer technology. He composed and co-produced all but two tracks on the album, which primarily features pop, dance, and R&B and discusses celebrity, romance, world peace, and self-improvement. The album features appearances from Siedah Garrett and Stevie Wonder.

Following the enormous success of his previous album, Thriller (1982), Jackson's public profile increased significantly. Bad represented a new phase in Jackson's career, as he faced greater expectations than ever before. He also reinvented himself, wearing distinctive Bad-era outfits featuring multiple buckles and straps. Jackson embarked on his first solo world tour, which grossed $125 million to become the highest-grossing concert tour at the time. Nine commercial singles were released along with a promotional single.

Bad remained atop the Billboard Top Pop Albums chart for six consecutive weeks and a record five of its singles reached number one on the US Billboard Hot 100: "I Just Can't Stop Loving You", "Bad", "The Way You Make Me Feel", "Man in the Mirror" and "Dirty Diana", while "Smooth Criminal" was also a Top 10 hit. Worldwide, it became the fastest-selling album in its first week, topped the charts in twenty-four other countries, and was the best-selling album of both 1987 and 1988. The album received acclaim from critics, particularly for Jackson's vocals and its musical arrangements, though some felt it lacked the "genius" of Thriller.

Bad is one of the best-selling albums of all time, with sales of over 35 million copies worldwide, and is certified 11× platinum in the US. It has been included in numerous lists of the greatest albums and praised as part of Jackson's influence on contemporary music. It was nominated for Album of the Year by the Grammy Awards and won Best Engineered Recording – Non Classical and Best Music Video (for "Leave Me Alone"). Jackson received the special Lifetime Achievement Award at the 1989 American Music Awards for the success.

American singer Michael Jackson released his sixth studio album, Thriller (1982), on November 29, 1982. By the end of 1983, it became the best-selling album of all time, with 32 million copies sold worldwide. The album's immediate success led to Jackson having a standing of cultural significance that was not attained by an African American before him in the history of the entertainment industry. The years that followed were marred by personal turmoil, including strained family ties, broken friendships with celebrities, a break with the Jehovah's Witnesses, and the pressures of global stardom. Jackson withdrew from the public eye for much of 1985 and 1986 but remained in headlines due to his eccentric behavior, including his adoption of a chimpanzee named Bubbles. Several rumors also circulated, including a false claim that he slept in a hyperbaric chamber.

According to those close to him, Jackson was anxious about finishing the follow-up to Thriller. Ken Tucker of NPR Music noted that it was nearly impossible for any album to replicate the unprecedented commercial success or cultural phenomenon of Thriller. In 2017, Newsweek described the challenge as "like following up the Bible". Despite the doubts of Jackson ever matching the impact and commercial success that Thriller achieved, he aimed to sell 100 million copies with his next album. The album's title, Bad, signified Jackson's shift from a youthful image to a tougher, more streetwise persona. Playwright Charles Fuller, who once met Jackson, noted that Jackson used "bad" to mean "great", as well as "tough" and "courageous". For the Bad era, Jackson reinvented his look with black clothing, buckles, and metal-studded belts, projecting a more edgy style. However, his changing appearance—including plastic surgery and a lighter complexion—sparked significant controversy, especially among American audiences.

Bad was Jackson's final collaboration with producer Quincy Jones, who had also worked on Off the Wall (1979) and Thriller. While Jackson had contributed a few songs to those albums, Jones encouraged him to write more for his next project. Reflecting on Jackson's growing personal struggles, Jones recalled: "All the turmoil [in Jackson's life] was starting to mount up, so I said I thought it was time for him to do a very honest album". Jackson wanted to pursue a new musical direction with Bad, aiming for a harder-edged and more aggressive sound. Guitarist Steve Stevens, who contributed to the album, recalled Jackson expressing interest in rock bands like Mötley Crüe. Jackson was eager to find innovative sounds and was interested in new music technology. As a result, the production team heavily used digital synthesizers, including FM synthesis, the Fairlight CMI, and the Synclavier PSMT, often layering different synths to create new sounds. The sessions also incorporated guitars, organs, drums, bass, percussion, saxophones, washboards and digital guitars. In Lily Rothman of Time's view, although following up Thriller posed a major challenge, Jackson was more involved than ever in the artistic process of Bad.

Jackson began recording demos and song ideas for the upcoming album in 1983, while simultaneously working on Victory (1984) with his brothers, the Jacksons. Throughout 1985 and 1986, he focused on writing and recording at his Hayvenhurst home studio in Encino, Los Angeles, alongside a group of musicians and engineers—comprising Bill Bottrell, Matt Forger, John Barnes, and Christopher Currell—referred to as the "B team". These demos were later brought to Westlake Studios, where such producers as Jones and engineer Bruce Swedien—dubbed the "A team"—completed the tracks. According to Jones, the sessions were so intense that the team would often work for days without rest: "They were carrying second engineers out on stretchers. I was smoking 180 cigarettes a day".