Majok was born in Sudan in 1987. He migrated to Sydney through a refugee camp in Egypt. Upon arrival in Sydney, he bonded with a group of young men also from Sudan, called the South Stars basketball team. He attended high school at St Aloysius' College and Parramatta Marist High School in Sydney, and the American International School in Carlingford where he graduated in 2008. After graduating, he committed to the University of Connecticut. He sat out during the 2008–09 season because he was not cleared to play by the NCAA. In January 2009, Majok joined the UConn roster and was eligible to practice with the squad for the remainder of the season, but was not able to play in games. In April 2009, he declared for the 2009 NBA draft but did not sign with an agent. About a week before the draft, he decided to withdraw his name and returned to UConn. On 20 December 2009, Majok made his debut with the Huskies. He scored one point and collected three rebounds in 16 minutes of action as a starter. In September 2010, Majok announced that he was leaving Connecticut, though the reasons as to why remain unclear. In 2009–10, he played in 26 games for the Huskies, averaging 2.3 points, 3.0 rebounds and 1.6 blocks per game.
Professional career
2010–11 season
In October 2010, Majok signed a two-month deal with FMV Isikspor Istanbul, a 2nd-division Turkish club. He played 7 games for them, averaging 13.9 points, 8.6 rebounds and 3.1 blocks in 28.3 minutes. After his contract expired, he left Turkey. On 24 December 2010, Majok signed a six-week deal with the Perth Wildcats of the Australian NBL as an injury replacement for Jesse Wagstaff and Matthew Knight. In 8 games for the Wildcats, Majok averaged 7.5 points, 2.8 rebounds and 2.0 blocks per game. Despite his short stint in Perth, Majok became a favourite amongst the Wildcats fans with due to his shot blocking ability, blocking a total of 11 shots in his first three games. On 12 February 2011, Majok signed with the Gold Coast Blaze for the rest of the 2010–11 season as an injury replacement for Mark Worthington. On 22 March 2011, just days before the Gold Coast's final home game of the 2010–11 NBL season against the Adelaide 36ers, Majok was released by the club so that he could advance his preparations and seek out training-camp opportunities in the United States prior to the 2011 NBA draft. In 6 games for the Blaze, he averaged 2.8 points and 2.3 rebounds per game.
2011–12 season
On 23 June 2011, Majok was selected by the Los Angeles Lakers with the 58th overall pick in the 2011 NBA draft. In August 2011, he signed with BK SPU Nitra of Slovakia for the 2011–12 season. In 41 league games for Nitra, he averaged 11.2 points, 8.1 rebounds, 2.6 blocks and 1.4 assists per game.
2012–13 season
Majok joined the Los Angeles Lakers for the 2012 NBA Summer League. In 3 games, he averaged 1.7 points, 4.3 rebounds and 1.3 blocks in 15 minutes per game. In September 2012, he signed a short-term deal with Maccabi Electra Tel-Aviv of Israel but left a month later before appearing in a game for them. In November 2012, he signed with BC Tsmoki-Minsk for the rest of the 2012–13 season. In 13 VTB United League games for Tsmoki-Minsk, he averaged 4.2 points, 4.2 rebounds and 1.1 blocks per game.
2013–14 season
On 3 September 2013, Majok signed with KCC Egis of Korea for the 2013–14 season. On 29 October 2013, he was released by Egis after just 12 games. The next day, he signed with Taiwan Beer for the rest of the season. On 12 November 2013, he was released by Taiwan Beer before appearing in a game for them. On 30 December 2013, he signed with BG Göttingen of Germany for the rest of the season. In 23 games for Göttingen, he averaged 4.3 points and 3.3 rebounds per game.
On 21 October 2016, he signed with Homenetmen Beirut of the Lebanese Basketball League. In 2017, he received the Lebanese citizenship and represented Lebanon in the 2017 West Asian Championship. In June 2017, he signed with the Luoyang Zhonghe of the Chinese National Basketball League. In his first game with Luoyang, Majok recorded 24 points, 20 rebounds and 7 blocks in a 123-138 loss to Anhui Wenyi.
2017–18 season
In October 2017, Majok signed with Sagesse Club of the Lebanese Basketball League. In June 2018, Majok signed with Shaanxi Xinda of the Chinese National Basketball League.
On 7 July 2016, Majok's draft rights were acquired by the Chicago Bulls in exchange for José Calderón and two future second-round draft picks. On 1 September 2017, Majok's draft rights were traded to the New Orleans Pelicans in exchange for the Chicago Bulls receiving Quincy Pondexter, a 2018 second round pick, and cash considerations. Majok's right was renounced by the Pelicans on 13 September.
