1928 in Japanese baseball
 Professional Baseball
 High School Baseball
The 14th National High School Baseball Championship featured a total of 410 schools competing for 22 spots in the finals at Koshien. In the championship game Matsumoto High School (Nagano) defeated Heian High School (Kyoto) by a score of 3 - 1.
The 5th National High School Baseball Invitational Tournament featured 16 schools competing in the tournament at Koshien. In the championship game Kansai Gakuin Central High School (Hyogo) defeated Wakayama Central High School (Wakayama) by a score of 2 - 1.
 University Baseball
 Tokyo Big6 Baseball League
The Keio team toured the United States in the spring and did not participate in the league.