G-Unit其实是由2003年发迹的50 Cent领导的一个纽约土生土长的说唱乐团,和50 Cent一样,这支乐团也是组建在纽约的皇后区。从本质上来说,G-Unit只是50 Cent的一个后备团,甚至说是啦啦队也可以,G-Unit和50 Cent几乎没有差别,比如在今年的MTV颁奖典礼上虽然说是50 Cent表演的《21 Questions》,但是实际上却是整个G-Unit在表演。
G-Unit成立比较早,在50 Cent爆发之前就已经成了很长时间了,最初只有三名成员,并不是照片上的三个人,而是50 Cent,Tony Yayo和Lloyd Banks,其中的Tony Yayo是比较富有经验的,他以前曾经跟随多位说唱明星做伴奏。三名成员在一起也是非常努力的创作和表演音乐,彼此间的配合也非常默契,同时他们还曾经录制国在小范围内播放的,非常受欢迎的磁带,但是在不久之后Tony Yayo因为非法持有枪支而被宣判入狱服刑,然后就由Young Buck代替了他在G-Unit乐团中的位置,并且一直继续表演和创作说唱音乐。
事实证明在Young Buck加入之后乐团进入了创作和表演的高峰期,他们创作的许多首单曲很受欢迎,此时也是G-Unit的说唱事业发展最快的时期。在50 Cent赖以成名的单曲《P.I.M.P.》以及专辑《Get Rich or Die Tryin'》中的多首单曲都是由Young Buck,Lloyd Banks甚至是Tony Yayo创作或者参与录制完成的。在50 Cent发财之后,他的G-Unit显然也顺势成为了聚光灯下的焦点,他们跟随50 Cent一起在各地表演,也包括在颁奖典礼上表演。G-Unit不久就在Interscope唱片公司获得了录制自己第一张专辑的机会,乐团在2003年10月14日的时候发行了第一支单曲《Stunt 101》,一个月之后,G-Unit的第一张专辑《Beg for Mercy》正式发行
2008年4月7日,50 Cent声明Young Buck不再属于G-Unit。
Though G-Unit became generally recognized as the brand name associated with 50 Cent, for instance serving as a catch phrase ("G-G-G-G-G-Unit!) as well as a record label (G-Unit Records), it in fact began as the name of his backing posse. G-Unit originally was a trio comprised of 50, Lloyd Banks, and Tony Yayo (often with the accompaniment of either DJ Whookid or Cutmaster C as their DJ), and this particular lineup resulted in a series of popular mixtapes during the early 2000s: 50 Cent Is the Future, God's Plan, No Mercy, No Fear, and Automatic Gunfire. Before the group had a chance to record its debut album for Interscope in the wake of 50's breakthrough with Get Rich or Die Tryin', Yayo was sentenced to prison for a gun-possession charge. His replacement, Young Buck, stepped up soon afterward, and the group continued its activity, working on yet more mixtape recordings and scoring some big-time success on the "G-Unit Remix" to 50's "P.I.M.P.," which also featured Snoop Dogg and got heavy rotation on MTV. Meanwhile, G-Unit recorded their debut album, Beg for Mercy, over the course of 2003, and Interscope finally rush-released the album on November 14 to combat bootlegging, preceding it with a lead single, "Stunt 101." Several other singles followed, including "Poppin' Them Thangs" and "Wanna Get to Know You." Yayo rejoined the group when he was released from prison in 2004. Other G-Unit affiliates included the Game, Olivia, and Mobb Deep. As 50's stature began diminishing in the late 2000s, however, several of his G-Unit affiliates either defected or were let go.