Adel was born in Juba under what is now South Sudan. As a youth, he, his mother and five siblings fled war-torn Sudan and moved to Uganda to set up a move to Australia when Deng was 8 years of age. He settled in Melbourne in 2004 and lived in the suburbs of Fitzroy and Sunshine. Basketball only came into Adel's life when his friends introduced him to it as a 14-year-old. From there, he began playing locally for the Sunshine Longhorns, and in 2012, he joined the Waverley Falcons' Big V team. Growing up, Adel also played soccer and ran track. Adel attended high school at both Keilor Downs College and Xavier College. In August 2013, he moved to the United States after landing a rare $20,000 basketball scholarship to Victory Rock Prep in Bradenton, Florida.
As a junior at Victory Rock Prep in 2013–14, Adel averaged 22 points and eight rebounds per game in helping the Blue Devils to a 24–8 record. In November 2014, Adel signed a National Letter of Intent to play college basketball for the University of Louisville. Adel considered offers from Connecticut, Florida, Mississippi and Virginia Tech before choosing to sign with the Cardinals. As a senior at Victory Rock Prep in 2014–15, Adel averaged 19.1 points, 8.2 rebounds and 4.0 assists per game in helping the Blue Devils to a 27–9 record. He subsequently earned all-state selection by the Florida Association of Basketball Coaches.
College career
In May 2015, Adel enrolled in classes and moved to the University of Louisville for the first session of summer school. He later joined the Louisville Cardinals for the 2015–16 season, and was made a starter for the team to begin his freshman campaign. He started for the Cardinals in the first two games of the season, averaging 4.5 points in 17 minutes while helping the team win both games. However, on 20 November, the day before the team's third game, Adel landed awkwardly in practice and was subsequently ruled out for three to six weeks with an MCL sprain in his left knee. He returned to full practice on 21 December, and made his return to the court the following night against UMKC. On 30 January 2016, he recorded season highs in points, rebounds and minutes played against Virginia. On 6 February, he had a season-best game with 13 points, 7 rebounds, 4 assists and 2 steals in 34 minutes as a starter in a 79–47 win over Boston College. As a junior, Adel led Louisville in scoring with 15.0 points per game and also pulled down 5.2 rebounds per game. After completing his junior year at Louisville, Adel announced his intentions on enter the 2018 NBA draft. Originally, he entered the draft without hiring an agent, but after a few weeks, he hired an agent of his own accord, thus removing any chance of him returning to Louisville for his senior year at the university.
After going undrafted in the 2018 NBA draft, Adel signed with the Houston Rockets for the NBA Summer League. On 14 September 2018, Adel signed with the Toronto Raptors on a training camp contract. After appearing in two preseason games, Adel was waived on 12 October. After being waived by Toronto, Adel spent the 2018-19 season playing for Toronto's G-League affiliate, Raptors 905. Through mid-December, he averaged 12.0 points and 5.4 rebounds in 31.3 minutes per game.
Cleveland Cavaliers/Canton Charge (2019)
On 15 January 2019, Adel signed with the Cleveland Cavaliers on a two-way contract. Adel made his NBA debut on 19 January 2019 against the Denver Nuggets, scoring three points with two rebounds in five minutes of play in a 124-102 loss.
On 30 July 2019, Adel signed with the Brooklyn Nets. On 14 October 2019, Adel was waived by the Nets. He then landed with the Long Island Nets. He scored a season-high 29 points in addition to 11 rebounds, two assists, two steals, and two blocks on November 29, in a loss to the Raptors 905. On 8 January 2020, he was sidelined against the Grand Rapids Drive with an undisclosed injury. Adel averaged 11.1 points, 4.2 rebounds and 2.7 assists per game.
The Hawks (2020–present)
On 23 July 2020, Adel signed with The Hawks of the National Basketball League.
Adel was eligible to represent both the Australian and South Sudanese national teams in international competitions, but made clear his intentions to represent Australia in 2015. On 24 May 2019 he was named in the Australian Boomers' squad for 2019 FIBA World Cup.
