1934 in Japanese baseball
 Professional Baseball
The Dai Nippon Tokyo Baseball Club is founded on December 26. The club will eventually become the Yomiuri Giants.
 High School Baseball
The 20th National High School Baseball Championship featured a total of 675 schools competing for 22 spots in the finals at Koshien. In the championship game Gokou Central High School (Hiroshima) defeated Kumamoto Kougyou (Kumamoto) by a score of 2 - 0.
The 11th National High School Baseball Invitational Tournament featured 20 schools competing in the tournament at Koshien. In the championship game Touhou High School (Aichi) defeated Naniwa High School (Osaka) by a score of 2 - 1.
 University Baseball
 Tokyo Big6 Baseball League
The league only held a single season.
 Tohto University Base Ball League
 Kansai 6 University Baseball League
The Kansai club suffered financial problems which caused its abstention from the league in 1934.
 International Baseball
The Babe Ruth and Lou Gehrig All-Stars, an American League all-star team, toured Japan in the fall of 1934. The touring team went 16 - 0 - 0 against Japanese competition. In the most famous game, Eiji Sawamura threw a one-hitter, only to lose 1-0 on a homer by Gehrig.