Results for Japan in 400 metres Freestyle, Men

Olympic and Intercalated results only.

Games	Athlete/Team	Placement
1920 Summer Olympics	Kenkichi Saito	AC h1 r2/3
	Masayoshi Uchida	3 h3 r1/3
1924 Summer Olympics	Kazuo Noda	13
	Katsuo Takaishi	DNS
1928 Summer Olympics	Katsuo Takaishi	4 h2 r2/3
	Hiroshi Yoneyama	5 h1 r2/3
	Nobuo Arai	2 h1 r1/3
1932 Summer Olympics	Tsutomu Oyokota	3	Bronze
	Takashi Yokoyama	4
	Noboru Sugimoto	5
1936 Summer Olympics	Shunpei Uto	2	Silver
	Shozo Makino	3	Bronze
	Hiroshi Negami	5
1952 Summer Olympics	Hironoshin Furuhashi	8
	Yasuo Tanaka	9
	Yoshio Tanaka	14
1956 Summer Olympics	Tsuyoshi Yamanaka	2	Silver
	Koji Nonoshita	7
	Yoshiro Noda	27
1960 Summer Olympics	Tsuyoshi Yamanaka	2	Silver
	Makoto Fukui	8
1964 Summer Olympics	Tsuyoshi Yamanaka	6
	Takeshi Yamakage	16
	Haruo Yoshimuta	17
1984 Summer Olympics	Shigeo Ogata	22
	Keisuke Okuno	27
1988 Summer Olympics	Yoshiyuki Mizumoto	32
	Shigeo Ogata	38
1992 Summer Olympics	Shigeo Ogata	24
	Masashi Kato	33
1996 Summer Olympics	Hisato Yasui	24
2000 Summer Olympics	Masato Hirano	11
2004 Summer Olympics	Takeshi Matsuda	8
2008 Summer Olympics	Takeshi Matsuda	10
2016 Summer Olympics	Naito Ehara	31