Following the success of 50 Cent's debut album, Get Rich or Die Tryin', he was granted his own record label, G-Unit Records.G-Unit, then consisting of Lloyd Banks, Tony Yayo and Young Buck, was signed to the label as a group, each respective member also being signed as a solo artist. Before G-Unit's signing with Interscope Records, Bang Em Smurf was very closely affiliated with the group. He claimed that the two recorded a mixtape from which they would earn $5 each; they sold 400,000 copies and 50 Cent allegedly never gave Bang Em' Smurf his share. Bang 'Em Smurf was never actually signed to G-Unit as an artist, but rather as an executive, or "under-boss," as he put it.
G-Unit's commercial debut, Beg For Mercy, sold 377,000 copies in its first week of release in 2003. It has now sold over 2.7 million units in the U.S. and 6 million copies worldwide. It has been certified double platinum by the RIAA.
After bringing in West Coast rapper and Aftermath signee, the Game in early 2004,Spider Loc was also signed, around the time of Young Buck's Straight Outta Cashville release. However, Game and 50 Cent later had a falling out, and 50 Cent became unsure about signing new artists to his "family"—how he perceived G-Unit as a group and record label. Later in 2007, the opportunity to sign Mobb Deep and M.O.P. was considered.
In 2006, G-Unit Records signed Young Hot Rod. In the same year, in conjunction with Mobb Deep's Infamous Records, the label signed both Nyce and 40 Glocc. In 2007, Mazaradi Fox was also added to the label. It was also highly anticipated that Detroit rapper, Trick Trick would sign to the label, though this deal never came to be.
In 2008, amidst rumors of a "beef" within G-Unit between 50 Cent and Young Buck, 50 Cent officially expelled Young Buck from the group, though assuring that Buck was still signed with the label. Numerous slander songs then arose on the internet from both camps, with Young Buck being included on a track with former rival and ex-G-Unit member, Game. 50 Cent then leaked a taped phone conversation between himself and Young Buck, which showed one of the true reasons for the falling out: 50 Cent was owed money by the Southern rapper. Young Buck later stated the conversation had taken place over a year before the leak. The two camps have since released a multitude of songs aimed at each other, though the feud seems to have settled down as of late 2008.
In late 2009, 50 Cent's fourth album, Before I Self Destruct, was released; which featured a track entitled "So Disrespectful", which insulted his various rivals including Jay-Z and former G-Unit Records artists, Game and Young Buck. Also in 2009, 50 Cent would collaborate with former Roc-A-Fella Records artist Beanie Sigel, which would also lead to speculation that Beanie Sigel was signing to G-Unit Records. While promoting Before I Self Destruct, 50 Cent also did a radio interview in which he spoke about the G-Unit Records roster. Within the interview, it was confirmed that Game, Young Buck, Spider Loc and Young Hot Rod were still signed to the label, while both M.O.P and Mobb Deep were no longer signed. In the meantime, the label would go on to sign R&B singer, Governor andBeanie Sigel on November 5, respectively.
In early January 2010, 50 Cent claimed that he was looking to sign new comedians and authors to the label, venturing outside the realm of recording artists.Atlanta Young Jack Thriller would be the first comedian signed to the label, releasing a weekly "So Disrespectful," YouTube podcast. also becoming a regular guest on Shade45's G-Unit Radio, and co-host of the program. 50 Cent also expressed interest in signing European R&B singer Jamelia to G-Unit Records, citing that it could not only help her build a reputation in the U.S., but it would also be the first signing of a female artist to the label since singer, Olivia. Also in early 2010, in reference to his recent affiliation with 50 Cent and G-Unit Records, Beanie Sigel stated that he would not be signing with the label, as he and 50 Cent mutually "used" each other, though no harm to their business relationship was made. Meanwhile, Young Buck responded to various songs released on 50 Cent's Before I Self Destruct. He released five records aimed at 50 Cent, Tony Yayo, Lloyd Banks, G-Unit, and 40 Glocc.
In an interview with MTV, 50 Cent announced that he is looking for new artists, "You'll see new faces, because I'm looking for new artists now. I'll sign new artists and take them with me and kinda groom them. Some of the stuff you can't teach a person; they gotta have it". While he was on tour, recently made affiliate Beanie Sigel confirmed after a long awaited wait, that he would be finished signing to G-Unit when 50 got back from tour.
In August 2010, amidst the controversy surrounding Montana Fishburne's entrance into the adult film industry, co-porn star, Brian Pumper, released several rap songs shouting out 50 Cent, Lloyd Banks and Tony Yayo. Pumper repeatedly stated his wish to be signed to G-Unit. However, the members of G-Unit have repeatedly stated they are not interested in signing Pumper. Also in August, Tony Yayo discussed how he and The Pack member, "Lil B," had hooked up and worked together in the studio, along with Yayo's newly proclaimed protoge, Danny Brown. He also stated that there was a large possibility that Lil B might be signing to G-Unit Records, and spoke as if Danny Brown was already signed. Despite this, Brown confirmed that he is not signed to G-Unit yet, but he is talks of possibly signing to the label. Also in September 2010, there was quite a bit of speculation that R&B singer, Mýa was in the process of signing to, or was already signed to the label. Lloyd Banks later in September would confirm that Mobb Deep member, Havoc was in talks to negotiate a new contract for the group in terms of signing to the label.
On August 13, 2010, in an interview with MTV News, Lloyd Banks announced that G-Unit had signed a limited distribution deal with EMI in North America. The distribution deal is "strictly with artists Lloyd Banks and Tony Yayo," as stated by 50 Cent in an interview.
In early March 2011, rapper Shawty Lo reported in an interview that he was in talks with the label about signing. On June 8, 2011, it was confirmed by both Shawty Lo and AllHipHop.com that he had signed a deal with G-Unit Records.
It was later confirmed by Shawty Lo that he had not signed to the label as an individual artist, but that his label D4L would be distributed by G-Unit Records.
Rumors began appearing that Lea Sunshine, the singer who was featured in Lil' Flip's hit single, "Sunshine", was signing to G-Unit. After touring with G-Unit and being featured on G-Note Records artist, Hot Rod's debut single, she confirmed on her Twitter account that she had signed with G-Note Records.
After a cameo appearance in Tony Yayo's music video, "Haters", it was reported by MTV that former Young Money affiliate, Kidd Kidd, had signed with the label. Soon after, Genasis reported via his Twitter that he had just inked a deal with 50 Cent and G-Unit Records after 50 Cent had seen a video of Genasis performing.
In December 2011, 50 Cent signed Jersey Shore star, DJ Pauly D, to G-Note Records, to produce three of label's albums.
 On December 9, 2011, 50 Cent also released a mixtape, The Big 10. Guest appearances on The Big 10 include G-Unit affiliates, Kidd Kidd, Precious Paris and Tony Yayo. It also introduced G-Units newest signee, Paris.
In the years to follow, 50 Cent would continue to struggle to maintain a palatable working relationship with Interscope. In a 2012 interview, he explained the reason for the discord: "The deal I gave them was so well-put-together for them that they were to receive $750,000 in advance on the next albums - each one of the artists. They gotta remove that in this climate of record sales".
In April 2012, (after being ousted from the crew in 2008), Young Buck entered talks to work with the label. Buck provided the update in a recent interview stating, "I'ma be honest with you, finally we're at a point where we're having some kind of negotiations with what they're going to be able to do for us at G-Unit." The Nashville, Tennessee native said he was ready to make a return to music, whether a part of G-Unit or not. Young Buck's last album was the 2010 independent release, The Rehab. The negotiations may not lead to a new deal between Young Buck and G-Unit, but the rapper remains optimistic.
On February 20, 2014, it was reported that 50 Cent and G-Unit Records left Interscope umbrella to operate in conjunction with Caroline Records; a unit of Capitol Music Group.
In early 2018, Kidd Kidd announced his departure from both G-Unit as a group member and label artist.
In 2010, G-Unit launched a subsidiary label called G-Note Records, with a focus on R&B and Pop music. Artists signed to this label are Governor, who was signed to G-Unit Records in 2009, and Hot Rod who originally signed to G-Unit Records in 2006. In early 2011, Lea Sunshine was signed to the label, though she later left the label. In December 2011, DJ Pauly D was signed to G-Note Records, but has since left the label.
On June 22, 2011 it was announced that Shawty Lo had signed the label to a distribution deal with 50 Cent's subsidiary label G-Unit South, for a worth of over $10 million.