Holmes started a career-high 33 games during the shortened 2019-20 season. For the first time in his career, Holmes averaged double figures in scoring (12.8 PPG) and posted career highs in both rebounds (8.3) and blocks (1.4) per game. The big man led the Kings in double-doubles before the All-Star break with 13. Holmes scored at least 20 points seven times after failing to accomplish that feat over the two past seasons with Phoenix and Philadelphia. On Oct. 28, Holmes recorded his first double-double of the season via 24 points, 13 rebounds and two blocks at home versus the Nuggets. On Dec. 26 against Minnesota, Holmes delivered 20 points, a career-high 18 rebounds, three assists, two steals and two blocks in a 1-point home loss to the Timberwolves. The 2015 second-round pick missed 25 games in January, February and March due to a shoulder injury. He returned on Mar. 7 for a win in Portland and generated 10 points, eight rebounds and a block in 19 minutes of run. After the injury, Holmes was able to appear in two games before the NBA season was suspended on Mar. 11. Holmes led the Kings in both rebounds and blocks per game.

Holmes spent his 2018-19 season with Phoenix following an offseason trade from Philadelphia. The fourth-year player made a career-high 70 appearances for the Suns, averaging 8.2 points and 4.7 rebounds. He scored his 1,500th career point on Jan. 15 against the Indiana Pacers. He also set new single-season career highs with 572 points, 331 rebounds and 79 blocks. Holmes scored in double-digits in four consecutive games in three different stretches during the season. He scored a season-high 19 points in a 123-119 overtime loss to the Clippers, where he also grabbed seven boards. He recorded four double-doubles on the season: 13 points and 10 rebounds vs. Brooklyn on Nov. 6, 10 points and 10 rebounds vs. Sacramento on Dec. 4, 12 points and 10 rebounds vs. Los Angeles Lakers on Jan. 27, and 12 points and 11 rebounds vs. Houston on March 15. He improved his free throw shooting to a career-best 73.1 percent, raising his career average to 70.6. Homes continued to show growth, as both his playing time and minutes played averages increased after the All-Star Break.

Holmes played a reserve role over 48 games with Philadelphia, averaging 15.5 minutes per contest and picking up two starts. His season got off to a delayed start due to a fractured wrist he suffered in the preseason. Holmes made his debut on Nov. 3, scoring 6 points across 10 minutes against Indiana. The 24-year-old wasn't heavily used on the offensive end, as he averaged 5.0 shots per game, but he did shoot an effective 56.0 percent from the field. That translated to 6.5 points per game, and Holmes scored in double figures 14 times. He also recorded 4.4 rebounds and 1.3 assists per contest. A bout with gastroenteritis cost Holmes four games in January. Holmes scored a season-high 19 points in a win over Milwaukee on April 11, knocking down 8-of-11 from the field. He had another highly efficient outing on Dec. 12 against Minnesota, finishing with 15 points on 6-of-11 shooting and also grabbing a season-high 11 rebounds. It was the only double-double of the year for the Bowling Green product. Holmes just missed out on two other double-doubles, as he twice scored in double figures and finished with nine rebounds. The 76ers ended the season with a mark of 52-30 and eliminated the Heat in the first round before losing to the Celtics in the Eastern Conference Semifinals. Holmes saw his first career playoff action and played briefly in three of Philly's 10 post-season contests.

Holmes saw significantly more playing time during the 2016-17 season, his second in The Association. The Philadelphia frontcourt reserve appeared in 57 games, with 17 starts, and increased his minutes per game from 13.8 last season to 20.9 in 2016-17. On Nov. 25, Holmes generated 13 points, five boards and three blocks in a loss to Chicago. In mid-December, Holmes was diagnosed with a concussion from an injury suffered in practice and missed 15 straight NBA games. During part of that absence, Holmes played six games with the G League Delaware 87ers and averaged 12.2 points, 6.7 rebounds and 1.5 blocks per G League contest. On Feb. 24, Holmes blocked a career-high five shots while double-doubling via 12 points and 10 rebounds in a win over the Wizards. Holmes registered five double-doubles for the season. An early-March injury to Jahil Okafor (knee) opened the door for Holmes to see more playing time through the end of the season. He started 13 of Philly's last 15 games and averaged 14.3 points and 7.5 boards over 29.4 minutes per game during that span. On March 11, Holmes came off the bench and scored a career-high 24 points, plus grabbed nine rebounds, in a road loss to the Clippers. Nine days later, Holmes started and double-doubled with a career-best-tying 24 points with a career-high 14 rebounds during a close loss at Orlando. On Mar. 29, Holmes scored a new career-high 25 points and grabbed eight boards in a seven-point loss to the Hawks.

Richaun Holmes was drafted in the second round (37th overall) by the Philadelphia 76ers in the 2015 NBA Draft. The 6-foot-10 rookie played in 51 games with one start and averaged 13.8 minutes per game. Holmes made his NBA debut on Opening Night, Oct. 28, with two points, three rebounds and one block during a loss at Boston. He registered his first NBA start on Nov. 9 and generated 11 points, three rebounds, one assists and two blocks in a home loss to the Bulls. However, a hamstring injury forced Holmes to miss 10 of Philly's next 12 games. On Dec. 28, the rookie scored a season-high 18 points, to go with three boards and three blocks, during a loss at Utah. On Feb. 10, the Bowling Green product blocked a season-best four shots in a loss to the Kings. On March 4, Holmes grabbed a season-high eight rebounds during a home loss to the Heat. The frontcourt reserve ended the season with per-game averages of 5.6 points, 2.6 rebounds and 0.8 blocked shots.