| Country: |  Japan |
| Dates: | August 28–September 6 |
| Num Teams: | 12 |
| Prev Year: | 2013 |
| Medal Type: | world minor |
| Num Championships: | 8 |
| Best Avg Hitter: | Shoki Katsumata |
| Best Avg: | .545 |
| Most Hr Hitter: |  Josh Naylor |
| Most Hr: | 3 |
| Most Sb Runner: | Wonjun Choi |
| Most Sb: | 7 |
| Most K Pitcher: | Sena Sato |
| Most K: | 28 |
| Games: | 50 |
| Attendance: | 65724 |
| Mvp: |  Nick Pratto |
| Prev Edition: | 2013 |
| Next Edition: | 2017 |
The 2015 U-18 Baseball World Cup was an international baseball tournament held by IBAF. The 2015 edition was held in Osaka, Japan from August 28, 2015 to September 6, 2015.
First Round: The twelve participating nations were drawn into two groups of 6, in which single round robin will occur. The top 3 nations from each group advances to the Second Round, while the bottom 3 nations from each group advance to the Consolation Round.
Consolation Round: The 6 nations in this round play one game against the teams they have not played yet. (example: The 4th placed team from Group A will play the bottom three teams from Group B)
Second Round: The format in the Second Round is similar to that of the Consolation Round. Each team plays the top three teams from the opposing group. (example: The 1st placed team from Group B will play the top three teams from Group A) The standings for this round will include the 2 games played against the 2 other Second Round qualifiers from the team's First Round group, and the 3 games played in the Second Round, for a total of 5 games. The 3rd and 4th-place finishers advance to the Bronze Medal Game, and the 1st and 2nd-place finishers advance to the Gold Medal Game.
Finals: The Finals consist of the Bronze Medal Game, contested by the 3rd and 4th-place finishers, and the Gold Medal Game, contested by the 1st and 2nd-place finishers.
| Tournament | [1] Mike Amditis Ian Anderson Daniel Bakst Will Benson Austin Bergner Jordan Butler Hagen Danner Braxton Garrett Kevin Gowdy Hunter Greene Cooper Johnson Reggie Lawson Morgan McCullough Mickey Moniak Nick Pratto Nick Quintana Ryan Rolison Blake Rutherford Cole Stobbe Forrest Whitley | [2] Wataru Funabiki Yuya Gunji Taiga Hirasawa Kengo Horiuchi Kanji Ito Shoki Katsumata Kotaro Kiyomiya Masato Morishita Kakeru Narita Shinnosuke Ogasawara Louis Okoye Sena Sato Ryo Shinohara Naruki Sugisaki Jumpei Takahashi Mikiya Takahashi Hiroshi Toyoda Shoki Tsuda Shotaro Ueno Koki Ugusa | [3] An Sang-hyun Choi Won-jun Choi Sung-young Choi Chung-yeon Ha Seong-jin Hwang Sun-do Im Suk-jin Joo Hyo-sang Kang Sang-won Kim Ju Sung Kim Deok-jin Kim Dae Hyun Kim Pyo-seung Lee Jin-young Lee Young-ha Park Jun-young Park Se-jin Park Sang-un Yoon Seong-pin Yu Jae-yu |
The following 12 teams qualified for the tournament. The number shown in parentheses is the country's position in the IBAF World Rankings going into the competition.
| width=200 | Pool A | width=200 | Pool B |
|---|---|---|---|
| (1) | (3) | ||
| (2) | (4) | ||
| (12) | (7) | ||
| (14) | (8) | ||
| (15) | (11) | ||
| (20) | (29) |
| width=150px | Teams | width=50px | width=50px | width=50px | Pct. | width=50px | GB | width=50px | width=50px | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| align=left | 5 | 0 | 1.000 | — | 54 | 1 | |||||||
| align=left | 4 | 1 | .800 | 1 | 32 | 8 | |||||||
| align=left | 3 | 2 | .600 | 2 | 33 | 22 | |||||||
| align=left | 2 | 3 | .400 | 3 | 22 | 46 | |||||||
| align=left | 1 | 4 | .200 | 4 | 16 | 40 | |||||||
| align=left | 0 | 5 | .000 | 5 | 14 | 54 |
|}
| width=150px | Teams | width=50px | width=50px | width=50px | Pct. | width=50px | GB | width=50px | width=50px | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| align=left | 5 | 0 | 1.000 | — | 42 | 13 | |||||||
| align=left | 4 | 1 | .800 | 1 | 28 | 8 | |||||||
| align=left | 3 | 2 | .600 | 2 | 30 | 29 | |||||||
| align=left | 2 | 3 | .400 | 3 | 33 | 15 | |||||||
| align=left | 1 | 4 | .200 | 4 | 17 | 38 | |||||||
| align=left | 0 | 5 | .000 | 5 | 15 | 62 |
|}1Game suspended and completed on September 2
| width=150px | Teams | width=50px | width=50px | width=50px | Pct. | width=50px | GB | width=50px | width=50px | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| align=left | 5 | 0 | 1.000 | — | 39 | 3 | |||||||
| align=left | 4 | 1 | .800 | 1 | 33 | 18 | |||||||
| align=left | 3 | 2 | .600 | 2 | 17 | 24 | |||||||
| align=left | 1 | 4 | .200 | 4 | 12 | 38 | |||||||
| align=left | 1 | 4 | .200 | 4 | 23 | 27 | |||||||
| align=left | 1 | 4 | .200 | 4 | 20 | 34 |
|}
| width=150px | Teams | width=50px | width=50px | width=50px | Pct. | width=50px | GB | width=50px | width=50px | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| align=left | 4 | 1 | .800 | - | 26 | 19 | |||||||
| align=left | 4 | 1 | .800 | - | 36 | 3 | |||||||
| align=left | 3 | 2 | .600 | 1 | 29 | 36 | |||||||
| align=left | 2 | 3 | .400 | 2 | 29 | 30 | |||||||
| align=left | 1 | 4 | .200 | 3 | 22 | 28 | |||||||
| align=left | 1 | 4 | .200 | 3 | 13 | 38 |
|}1Game suspended and completed on September 4
|}
|}1The game was originally scheduled to begin at 18:10, but was delayed by rain.