The 2021 Washington Mystics season was the franchise's 24th season in the Women's National Basketball Association (WNBA). The regular season tipped off versus the Chicago Sky on May 15, 2021.
The Mystics struggled to start the season only winning two of their six games in the month of May. Their fortunes rebounded when they posted a .500 winning percentage through June and in their two games in July before the Olympic break. In closing out their pre-Olympic schedule they won in overtime versus the Chicago Sky to finish the first portion of the schedule with an 8–10 record. Coming back from the break, they faced a tough schedule and posted a 2–6 record, including losing the first four games back from the break. To close out the season, September contained two wins book marked by two losses on either side. Going into the last day of the season, the Mystics had a chance to secure a playoff spot, but lost to the Minnesota Lynx to miss the playoffs and finish with a 12–20 record. Tina Charles was a bright spot during the season, as she led the league in scoring.
Transactions
WNBA draft
Due to a trade in 2020 for C Tina Charles, the Mystics did not make a selection in the 2021 Draft.
Trades and roster changes
Roster
Game log
Preseason
|- style="background:#fcc;" | 1 | May 5 | Atlanta | L 80–87 | Tina Charles (18) | Jillian Alleyne (12) | Natasha Cloud (3) | Entertainment and Sports Arena0 | 0–1 |- style="background:#fcc;" | 2 | May 8 | @ Minnesota | L 68–79 | Tina Charles (18) | Jillian Alleyne (8) | Natasha Cloud (4) | Target Center No Fans | 0–2
Regular season
|- style="background:#fcc;" | 1 | May 15 | Chicago | L 56–70 | Tina Charles (14) | Erica McCall (9) | CloudMitchell (3) | Entertainment and Sports Arena1,050 | 0–1 |- style="background:#fcc;" | 2 | May 18 | Phoenix | L 70–91 | Tina Charles (22) | Tina Charles (12) | Leilani Mitchell (7) | Entertainment and Sports Arena1,050 | 0–2 |- style="background:#cfc;" | 3 | May 21 | New York | W 101–72 | Tina Charles (34) | Tina Charles (13) | Natasha Cloud (8) | Entertainment and Sports ArenaNo Fans | 1–2 |- style="background:#fcc;" | 4 | May 23 | @ Indiana | L 77–89 | Tina Charles (31) | CharlesMcCall (9) | Ariel Atkins (4) | Bankers Life FieldhouseNo Fans | 1–3 |- style="background:#cfc;" | 5 | May 25 | @ Indiana | W 85–69 | Tina Charles (30) | Myisha Hines-Allen (10) | Natasha Cloud (7) | Bankers Life FieldhouseNo Fans | 2–3 |- style="background:#fcc;" | 6 | May 28 | @ Connecticut | L 81–86 | Tina Charles (29) | Myisha Hines-Allen (10) | CharlesCloudHines-Allen (3) | Mohegan Sun Arena2,102 | 2–4
|- style="background:#fcc;" | 7 | June 5 | Las Vegas | L 93–96 | Myisha Hines-Allen (32) | Myisha Hines-Allen (13) | Natasha Cloud (11) | Entertainment and Sports Arena2,100 | 2–5 |- style="background:#cfc;" | 8 | June 8 | Minnesota | W 85–81 | Tina Charles (31) | Tina Charles (8) | Natasha Cloud (8) | Entertainment and Sports Arena2,100 | 3–5 |- style="background:#cfc;" | 9 | June 10 | Los Angeles | W 89–71 | Ariel Atkins (23) | Tina Charles (10) | Natasha Cloud (5) | Entertainment and Sports Arena2,100 | 4–5 |- style="background:#fcc;" | 10 | June 13 | @ Atlanta | L 78–101 | Myisha Hines-Allen (16) | CharlesLeslie (7) | Natasha Cloud (6) | Gateway Center Arena1,122 | 4–6 |- style="background:#cfc;" | 11 | June 17 | Atlanta | W 96–93 | Ariel Atkins (32) | Natasha Cloud (9) | Natasha Cloud (11) | Entertainment and Sports Arena2,100 | 5–6 |- style="background:#cfc;" | 12 | June 19 | Indiana | W 82–77 | Tina Charles (30) | Tina Charles (15) | Theresa Plaisance (4) | Entertainment and Sports Arena2,100 | 6–6 |- style="background:#cfc;" | 13 | June 22 | @ Seattle | W 87–83 | Tina Charles (34) | Tina Charles (16) | Leilani Mitchell (7) | Angel of the Winds Arena2,495 | 7–6 |- style="background:#fcc;" | 14 | June 24 | @ Los Angeles | L 82–89 | Leilani Mitchell (26) | Tina Charles (10) | Ariel Atkins (7) | Los Angeles Convention Center520 | 7–7 |- style="background:#fcc;" | 15 | June 26 | @ Dallas | L 74–85 | Tina Charles (27) | Tina Charles (10) | Leilani Mitchell (7) | College Park Center2,055 | 7–8 |- style="background:#fcc;" | 16 | June 29 | Connecticut | L 71–90 | Tina Charles (26) | Theresa Plaisance (7) | Ariel Atkins (5) | Entertainment and Sports Arena2,100 | 7–9
|- style="background:#fcc;" | 17 | July 3 | @ New York | L 79–82 | Tina Charles (31) | Tina Charles (16) | Shavonte Zellous (5) | Barclays Center1,615 | 7–10 |- style="background:#cfc;" | 18 | July 10 | @ Chicago | W 89–85 (OT) | Tina Charles (34) | Tina Charles (17) | Natasha Cloud (11) | Wintrust Arena8,331 | 8–10