Alain David Jourgensen (born Alejandro Ramírez Casas; October 9, 1958) is a Cuban-American singer, musician and music producer. Closely related with the independent record label Wax Trax! Records, his musical career spans five decades. He is the frontman and lyricist of the industrial metal band Ministry, which he founded in 1981 and of which he remains the only constant member. He was the primary musician of several Ministry-related projects, such as Revolting Cocks, Lard, and Buck Satan and the 666 Shooters. Jourgensen is a prominent figure in industrial music, influencing numerous other groups and musicians, both in alternative and industrial-associated acts.

Born in Havana shortly before the Cuban Revolution of 1959, at the age of three Jourgensen moved to the United States with his family, and was raised mainly in Chicago and Breckenridge, Colorado. He developed an interest in music at a young age, and was involved in several short-lived bands, as well as briefly performing in the backing band of drag performer Divine.

Jourgensen formed Ministry in 1981 in Chicago and received significant attention from music press regarding the band's 1983 debut studio album, With Sympathy. His subsequent releases in the 1980s, most prominently Ministry's The Land of Rape and Honey (1988) and The Mind Is a Terrible Thing to Taste (1989), showcased his stylistic transition; in the early 1990s, he achieved mainstream success with Ministry's fifth studio album, Psalm 69: The Way to Succeed and the Way to Suck Eggs (1992). The next few years were marked by publicity surrounding Jourgensen's substance abuse which negatively affected his creative output and resulted in a period of severe depression; during this time, Jourgensen and Ministry appeared in the 2001 Steven Spielberg film A.I. Artificial Intelligence.

In 2005, Jourgensen established his own record label, 13th Planet Records, through which several Ministry records, among others, were released until the early 2010s. As of 2025, Jourgensen and Ministry are signed to Cleopatra Records.

Alejandro Ramírez Casas was born in Havana, Cuba, on October 9, 1958, the son of Margarita "Maggie" Brouwer (born c. 1942) Jourgensen, who is of Dutch and Spanish heritage, says he does not remember anything about his real father. In 1961, following the fall of Fulgencio Batista's regime and rise of Fidel Castro to power, his family relocated to the US. In 1964, Brouwer married Ed Jourgensen, a stock car driver and mechanic for Formula One driver Dan Gurney. She adopted his surname, which is Norwegian, for herself and her son.

Jourgensen was raised in Chicago, Illinois, and Breckenridge, Colorado, attending Greeley High School and Summit County High School in Frisco, Colorado, in 1976. He was a fan of a wide range of artists including the Beatles, Pink Floyd, Hawkwind, Led Zeppelin, Hank Williams and George Jones. After seeing the Ramones on stage in Denver, Jourgensen decided to be a punk musician.

Jourgensen eventually attended the University of Illinois Chicago, after briefly enrolling at both the University of Northern Colorado and the University of Colorado.

Jourgensen formed Ministry in 1981 after leaving Special Affect, a post-punk band that included Frankie Nardiello, founding member (as Groovie Mann) of My Life With The Thrill Kill Kult and drummer Harry Rushakoff of Concrete Blonde). Early singles by Ministry and Jourgensen's other projects were released on Wax Trax! Records. He also produced Skinny Puppy's Rabies album. During that time, Jourgensen befriended Nivek Ogre, who later toured with Ministry.