The 2021 WNBA season was the 24th season for the Phoenix Mercury of the Women's National Basketball Association. The season tipped off on May 14, 2021, at the Minnesota Lynx.^[1]

The team returned to the newly renovated Phoenix Suns Arena this season. Originally the team had planned to be elsewhere for the 2021 season, but renovations were finished ahead of schedule.^[2]

The start to the season was a mixed bag for the Mercury. They went 3–3 during the first month of the season. June was a streaky month for the team as they won the first two games, but then went on a four game losing streak. The streak was broken by two wins, but followed by a loss to finish the month 4–5. The Mercury lost the first game of July, won the middle two, and lost the last game before the Olympic break. They went into the Olympic break with a 9–10 overall record. The Mercury had a spectacular return from the Olympic break, winning all seven of their games in August. Of the seven games only three were against playoff teams, and two of those three were against the eventual eight seed, New York Liberty. The Mercury extended their winning streak into September, and won their first three games of the month. However, their last three games of the season were against the eventual first, second, and fourth seeded playoff teams, and the Mercury lost all three games to finish the month 3–3. They finished with an overall record of 19–13 and secured the fifth overall seed in the playoffs.

As the fifth seed in the playoffs, the Mercury did not receive a bye played in the First Round. They defeated eight seed New York 83–82 in a close game. As the higher remaining seed in the second round, they traveled to Seattle to face off against the fourth seeded Storm. The Mercury advanced in a thrilling overtime game, 85–80. As the highest seed to advance from the second round, the Mercury played the second seeded Las Vegas Aces in the Semifinals. In a back and forth series the Mercury won games two, three, and five to win the series 3–2 and advance to the Finals. In the Finals, the team faced the Chicago Sky. The Mercury had home court advantage, meaning the first two games were played in Phoenix. The Mercury split those games 1–1 and the series advanced to Chicago. The Sky won both the games at home, and the series 3–1.

Notes

(#) – League Standing

x – Clinched playoff berth

e – Eliminated from playoff contention

Source: Overall standings and Commissioner's Cup Standings

Note: Teams re-seeded after each round.

Source:^[24]