- I Knew It!: Many people expected Pauline to make her playable debut in Mario Tennis Aces, given that the game was announced following her greatly expanded role in Super Mario Odyssey. Although she wasn't one of the playable characters at release, she was among the additional characters that were added after release, becoming available in March 2019.
- Fan Nickname:
- Yoshi Tennis Open to the 3DS game because of the overabundance of many Yoshi colors as singular characters.
- The Wii U game is often called Mario Tennis: Ultra Trash, due to its bare-bones content.
- Lucien, the racket in Adventure Mode, has been called "Infinity Racket" due to its golden color scheme and five slots where its "Power Stones" are placed making it eerily similar to the Infinity Gauntlet.
- Spike, introduced in Aces, is more frequently referred to by his fan nickname, Fishy Boopkins.
- What Could Have Been: During development of the original game, there was talk of expanding the Waluigi concept further by making an evil counterpart for Peach, tentatively known as "Warupeach" or "Wapeach".
Trivia / Mario Tennis