Here is a list of Mayer's best fights. For a list of Mayer's losses, refer to "Mikaela Mayer Losses".
On November 5, 2021 Mikaela Mayer, the WBO champion, met Maïva Hamadouche, the IBF and The Ring champion, in a super-featherweight world-title unification fight. Mayer was 31 years old and with a record of 16-0 (5), and Hamadouche was 32 years old and with a record of 22-1 (18). Mayer won the fight via 10-round unanimous decision and and is crowned the unified WBO, IBF and The Ring champion.
On April 9, 2022 Mikaela Mayer met Jennifer Han in a super-featherweight (WBO, IBF and The Ring) world-title defense fight. Mayer was 31 years old and with a record of 17-0 (5), and Han was 38 years old and with a record of 18-4-1 (1). Mayer won the fight via 10-round unanimous decision and successfully defended her titles.
On June 19, 2021 Mikaela Mayer met Érica Farías in a super-featherweight (WBO) world-title defense fight. Mayer was 30 years old and with a record of 15-0 (5), and Farías was 36 years old and with a record of 26-4 (10). Mayer won the fight via 10-round unanimous decision and successfully defended her title.
On March 29, 2025 Mikaela Mayer met Sandy Ryan in a welterweight (WBO) world-title defense fight. Mayer was 34 years old and with a record of 21-2 (5), and Ryan was 31 years old and with a record of 7-2-1 (3). Mayer won the fight via 10-round unanimous decision and successfully defended her title.
On September 27, 2024 Mikaela Mayer fought Sandy Ryan in a welterweight world-title fight for Ryan's WBO title. Mayer was 34 years old and with a record of 20-2 (5), and Ryan was 31 years old and with a record of 7-1-1 (3). Mayer won the fight via 10-round majority decision and is crowned the new welterweight world champion.