Siakam played college basketball for the New Mexico State Aggies and was named the Western Athletic Conference Player of the Year in 2016.

The following year, Siakam led Toronto to the second-best record in the league, earning All-NBA Second Team while being named a starter in his first NBA All-Star Game.

[2] Siakam initially had little interest in basketball in stark contrast to his older brothers, all of whom earned scholarships with the sport to various NCAA Division I colleges.

[2] He was discovered as a player at a local camp by Luc Mbah a Moute, whose parents' home in Bafia was about 2 miles (3 km) from St. Andrew's.

There, despite having had virtually no basketball experience at the time, he gained attention for his apparent athleticism and extremely high energy level.

After redshirting the 2013–14 season due to injury, he worked his way onto the Aggies' starting lineup and then to Western Athletic Conference (WAC) Freshman of the Year honors by the 2014–15 campaign.

For the 2015–16 campaign, he averaged 20.2 points, 11.6 rebounds, and 2.2 blocks across 34 games en route to earning unanimous WAC Player of the Year honors.

[5] On 23 June 2016, Siakam was selected by the Toronto Raptors with the 27th overall pick in the NBA draft,[6] with the franchise signing him to a rookie scale contract on 9 July.

[7] On October 26, he became the first rookie to start for the Raptors' season-opener since Jonas Valančiūnas did so in 2012; rising to the occasion, he hauled in 9 rebounds and notched 4 points in 21 minutes as Toronto beat the Detroit Pistons, 109–91.

[9] In his rookie season, Siakam started in as many as 38 games at power forward, including the first 35 of the 2016–17 campaign, because Jared Sullinger was out with injury;.

[10] Accordingly, between games played for the Raptors, he led Toronto's affiliate team to the finals and helped them win a title by defeating the Rio Grande Valley Vipers 2–1 in the series.

[9] He drew comparisons to Warriors' forward Draymond Green for such qualities as his rare ability to guard all positions, his shrewd basketball knowledge, and internal confidence.

[13] Heading into the 2018–19 campaign, Siakam emerged as a two-way force, and he averaged 16.9 points a night to go along with 6.9 rebounds and 3.1 assists; he also made a marked improvement in shooting from distance, increasing his three-point percentage by 36%.

[18] On 13 February, he racked up a new career-high 44 points and hit a career-best 4 three-pointers in a 129–120 win over the Wizards; he thus became the 11th Raptor in franchise history to reach the 40-point plateau.

[21] In Game 3 of the Eastern Conference Finals, Siakam helped Toronto defeat Milwaukee in double-overtime, 118–112, putting up 25 points and bringing down 11 rebounds; the win cut the Bucks' series lead to 2–1.

[22] In Game 6, Siakam converted 18 points for his part in the 100–94 win over Milwaukee; the victory clinched the series and propelled the Raptors to the NBA Finals for the first time in franchise history.

[23] In Game 1 of the 2019 Finals, Siakam scored a then playoff career-high 32 points with 8 rebounds, 5 assists and 2 blocks on 14-of-17 shooting from the field in a 118–109 victory over the Golden State Warriors.

[27] Siakam recorded 34 points, 18 rebounds, 5 assists, and 1 block in 38 minutes played of the NBA's season-opening game to help the Raptors beat the New Orleans Pelicans 130–122.

[43] On November 7, 2021, Siakam made his season debut coming off surgery scoring 15 points on a minutes restriction against the Brooklyn Nets.

[52][53] On February 12, Siakam scored a then season-high 35 points, grabbed 10 rebounds, dished out 7 assists and had 2 steals in a 110–109 loss to the Denver Nuggets.

[54] On March 28, Siakam scored 25 of his season-high 40 points in the first half, grabbed 13 rebounds along with 3 steals and 2 blocks in a 115–112 overtime win over the Boston Celtics.

[55] On April 7, Siakam recorded his third career triple-double with 37 points, 11 rebounds, 12 assists and 2 steals prompted the home fans to chant "MVP"in a 119–114 win over the Philadelphia 76ers .

[72][73] On November 2, Siakam recorded his fifth career triple double with 22 points, 10 rebounds and 11 assists in a 143–100 blowout win over the San Antonio Spurs.

[83] Two days later, on January 19, Siakam made his Pacers debut, putting up 21 points, six rebounds and three assists in a 118–115 loss against the Portland Trail Blazers.

[94] Siakam came into the NBA as a raw prospect but over the years has emerged as a high-end two-way wing player with playmaking and scoring ability, playing a variety of roles depending on the needs of the team.

Inspired by Siakam's iconic spin move and the Raptors team colours, it is made with vanilla soft serve, hot fudge, and crushed red Smarties.