Island Open
The Island Open is the big tournament in Mario Tennis and Mario Tennis: Power Tour. The tournament itself is divided into singles and doubles tournaments between the Academy, the Union, the Empire, and the Factory.
Game Boy Color
Each match is 5 sets and 6 games long. Unseeded players must start in round one while seeded players are given a bye to round two.
Singles
In singles, the player will battle in order: Sammi, Spike, Emily, and lastly A. Coz.
| Singles | |||||
|---|---|---|---|---|---|
|
School | Seed No. | Character | Result | 
|
| Academy | |||||
| -- | Alex/Nina | Winner | |||
| 2 | Emily | Lost the semifinal to Alex/Nina. | |||
| 1 | Kevin | Third place. Lost the semifinal to A. Coz. | |||
| 3 | Mark | Lost round two to A. Coz. | |||
| Union | |||||
| -- | Sammi | Lost round one to Alex/Nina. | |||
| -- | Sean | Lost round one to Frank. | |||
| Empire | |||||
| -- | Elden | Lost round one to A. Coz. | |||
| -- | Ellis | Lost round one to B. Coz. | |||
| 4 | Spike | Lost round two to Alex/Nina. | |||
| Factory | |||||
| -- | A. Coz | Runner-up. Lost the final to Alex/Nina. | |||
| -- | B. Coz | Lost round two to Emily. | |||
| -- | Frank | Lost round two to Kevin. | |||
Doubles
In doubles, the player's team will battle in order: Sammi and Sean, Spike and Elden, and lastly A. Coz and B. Coz.
| Doubles | |||||
|---|---|---|---|---|---|
|
School | Seed No. | Team | Result | 
|
| Academy | |||||
| -- | Alex/Nina and Harry/Kate | Winners | |||
| 1 | Kevin and Emily | Lost the semifinal to A. Coz. and B. Coz. | |||
| Union | |||||
| -- | Sammi and Sean | Lost round one to Alex/Nina and Harry/Kate. | |||
| Empire | |||||
| -- | Ellis and Edgar | Lost round one to A. Coz. and B. Coz. | |||
| 2 | Spike and Elden | Lost the semifinal to Alex/Nina and Harry/Kate. | |||
| Factory | |||||
| -- | A. Coz and B. Coz | Runners-up. Lost the final to Alex/Nina and Harry/Kate. | |||
Game Boy Advance
Each match is 5 sets and 2 games long. In singles, unseeded players must start in round one while seeded players are given a bye to round two. In doubles, as there are a balanced number of teams, all teams start in round one. Dweezil is the defending champion of both the singles and (along with Mynx) the doubles championships.
Singles
In singles, the player will battle in order: Barb, Sass, Elroy, and lastly Willy.
| Singles | |||||
|---|---|---|---|---|---|
|
School | Seed No. | Character | Result | 
|
| Academy | |||||
| -- | Clay/Ace | Winner | |||
| 2 | Elroy | Third place. Lost the semifinal to Clay/Ace. | |||
| -- | Whisker | Lost round one to Chas. | |||
| Union | |||||
| -- | Chas | Lost round two to Mynx. | |||
| -- | Leon | Lost round one to Sheri. | |||
| -- | Mel | Lost round one to Willy. | |||
| Empire | |||||
| -- | Barb | Lost round one to Clay/Ace. | |||
| 1 | Dweezil | Lost round two to Willy. | |||
| 3 | Mynx | Lost the semifinal to Willy. | |||
| Factory | |||||
| 4 | Sass | Lost round two to Clay/Ace. | |||
| -- | Sheri | Lost round two to Elroy. | |||
| -- | Willy | Runner-Up. Lost the final to Clay/Ace. | |||
Doubles
In doubles, the player's team will battle in order: Chas and Mel, Dweezil and Mynx, and lastly Willy and Sheri.
| Doubles | |||||
|---|---|---|---|---|---|
|
School | Seed No. | Team | Result | 
|
| Academy | |||||
| -- | Clay and Ace | Winners | |||
| 2 | Elroy and Tori | Lost the semifinal to Willy and Sheri. | |||
| Union | |||||
| -- | Chas and Mel | Lost round one to Clay and Ace. | |||
| -- | Leon and Peter | Lost round one to Elroy and Tori. | |||
| Empire | |||||
| 1 | Dweezil and Mynx | Third place. Lost the semifinal to Clay and Ace. | |||
| -- | Oscar and Barb | Lost round one to Willy and Sheri. | |||
| Factory | |||||
| -- | Sass and Chet | Lost round one to Dweezil and Mynx. | |||
| -- | Willy and Sheri | Runners-up. Lost the final to Clay and Ace. | |||
Trivia
- In Mario Tennis: Power Tour, it is shown that Alex is canonically the winner of the singles and (along with Harry) the doubles championships of the Island Open.
- Between both games, the only Union player to make it past round one is Chas.
- The singles championship of Mario Tennis: Power Tour is the only time the player is not on the top-left of the bracket.
- As there are no mentions of any third-place matches, the third place trophies are shown to go to the players who lost the semifinal round to the eventual winner of the tournament.
