Sampson attended St. Vincent–St. Mary High School in Akron, Ohio from 2007 to 2010, before transferring to Brewster Academy in August 2010 for his senior year. In November 2010, he signed a National Letter of Intent to play college basketball at St. John's University. As a senior in 2010–11, Sampson averaged 15.0 points, 7.0 rebounds and 3.0 blocks per game, leading Brewster to a 31–3 record. He went on to be named to the All-NEPSAC first team. Following the 2010–11 season, Sampson was set to join the St. John's Red Storm in 2011–12 for his freshman season, but failed to qualify academically and was ineligible to attend college. Sampson subsequently returned to Brewster Academy for another season, and led Brewster to a prep national championship. In 2011–12, he averaged 18.5 points and 11.0 rebounds per game as he was named the NEPSAC AAA Player of the Year and Most Valuable Player of the National Prep Championship. In March 2012, Sampson recommitted to St. John's.
College career
In his freshman season at St. John's, Sampson was named the 2013 Big East Rookie of the Year, and was also named to the Big East All-Rookie team. In 33 games, he averaged 14.9 points, 6.6 rebounds, 1.1 assists, 1.1 steals and 1.1 blocks in 31.5 minutes per game. In his sophomore season, he recorded 424 points and 202 rebounds, completing his Red Storm career with totals of 915 points and 420 rebounds. He was named to the 2013 Pre-season All-Big East second team. In 33 games, he averaged 12.8 points, 6.1 rebounds, 1.2 assists and 1.0 blocks in 29.0 minutes per game. On March 24, 2014, Sampson announced his intentions to enter the 2014 NBA draft and forgo his final two years of college eligibility.
After going undrafted in the 2014 NBA draft, Sampson joined the Philadelphia 76ers for the 2014 NBA Summer League. On September 29, 2014, he signed with the 76ers. On November 21, 2014, he was assigned to the Delaware 87ers, the 76ers' D-League affiliate. Three days later, he was recalled by the 76ers. On February 18, 2016, he was waived by the team.
On February 22, 2016, Sampson signed with the Denver Nuggets. The next day, he made his debut with the Nuggets in a 114–110 loss to the Sacramento Kings, recording one rebound and one steal in fourteen minutes off the bench. On October 15, 2016, he was waived by the Nuggets.
On July 29, 2017, Sampson was signed to a two-way contract by the Sacramento Kings of the NBA. Under the terms of the deal, for the 2017–18 season, he will have a one-year deal splitting time between the Kings and their G-League affiliate, the Reno Bighorns. On December 6, 2017, Sampson grabbed a career-high 16 rebounds in a loss to the Cleveland Cavaliers. Sampson played 35 games with the Bighorns and averaged 17.9 points, 7.1 rebounds and 1.06 steals per game.
On September 24, 2018, Sampson signed with the Chicago Bulls for training camp. He was waived by the Bulls on October 12, 2018. On October 20, 2018, the Windy City Bulls announced that they had acquired the returning right to Sampson Johnson and the No. 38 overall pick in the 2018 NBA G League Draft, Mike Amius from Iowa Wolves for the returning rights to Jarell Eddie and Jaylen Johnson, and later on November 9, 2018, the Windy City Bulls acquired Sampson.
On January 29, 2019, the Windy City Bulls re-acquired Sampson.
Chicago Bulls (2019)
On March 31, 2019, the Chicago Bulls announced that they had signed Sampson to a 10-day contract. Over four games with the Bulls, Sampson averaged 20.0 points and 8.0 rebounds off the bench.
Shandong Heroes (2019)
On July 4, 2019, Sampson signed with the Shandong Heroes of the Chinese Basketball Association.
Indiana Pacers (2019–present)
On August 2, 2019, Sampson signed a 1-year deal worth $1,737,145 with the Indiana Pacers.
Career statistics
NBA
Regular season
College
Personal life
Sampson is the son of Dawnette Epps and Darrel Sampson, and has two brothers, D. J. and Justin. Through his college career, the Akron native was nicknamed SpongeBob Sampson.
