Ippei Kojima (born 1944) is a former Japanese badminton player who won a record eight Japanese national men's singles titles and some major international titles in both singles and doubles between the mid-1960s and the mid-1970s.
His game was marked by exceptional foot speed, great tenacity, and power surprising for a man who was about five feet (1.524 meters) tall. Kojima is the first of only two Japanese players to have won men's singles at the prestigious Danish Open (1970). He also shared the Danish Open men's doubles title, with different partners, in 1968 and 1969. In 1970 he reached the final of all three events at both the U.S. and Canadian Open championships, winning men's doubles in the U.S. and both singles and mixed doubles in Canada. In 1971 he won men's singles at the Singapore Open and over a select international field at the Flare Square Invitational, a one-time-only event held in conjunction with the Calgary (Canada) Stampede, where he defeated Denmark's Svend Pri in the final. Perhaps the most notable matches of Kojima's career were a series of close but losing singles efforts against the iconic Rudy Hartono in Thomas Cup, the All-Englands, and other major venues in 1970 and 1971.
|1970||Indoor Stadium Huamark, Bangkok, Thailand||Muljadi||15–17, 15–11, 10–15||Bronze|
|1968||Malaysia Open||Tan Aik Huang||4–15, 15–13, 6–15||Runner-up|
|1968||Singapore Open||Tan Aik Huang||12–15, 4–15||Runner-up|
|1970||Denmark Open||Erland Kops||15–3, 15–10||Winner|
|1970||US Open||Junji Honma||15–13, 8–15, 8–15||Runner-up|
|1970||Canada Open||Junji Honma||15-11, 9-15, 15-6||Winner|
|1971||Denmark Open||Rudy Hartono||18–14, 14–15, 11–15||Runner-up|
|1971||Canada Open||Rudy Hartono||7–15, 2–15||Runner-up|
|1971||Flare Square Invitational||Svend Pri||15–3, 15–4||Winner|
|1971||Singapore Open||Nunung Murdjianto||15–3, 18–16||Winner|
|1972||Denmark Open||Svend Pri||9–15, 5–15||Runner-up|
|1968||Malaysia Open||Issei Nichino|| Tan Yee Khan
Ng Boon Bee
|15–11, 9–15, 9–15||Runner-up|
|1968||Denmark Open||Issei Nichino||Winner|
|1969||Denmark Open||Bjarne Andersen|| Tan Aik Huang
Tan Aik Mong
|15–9, 6–15, 15–7||Winner|
|1969||US Open||Channarong Ratanaseangsuang|| Punch Gunalan
Ng Boon Bee
|1970||Canada Open||Junji Honma|| Channarong Ratanaseangsuang
|1970||US Open||Junji Honma|| Don Paup
|1971||Singapore Open||Junji Honma|| Ade Chandra
|1970||US Open||Machiko Aizawa|| Paul Whetnall
|1970||Canada Open||Susan Whetnall|| Paul Whetnall
|10–15, 15–5, 15–13||Winner|
- Herbert Scheele, The International Badminton Federation Handbook for 1971 (Canterbury, Kent, England: J. A. Jennings Ltd., 1971) 152, 153.
- Herbert Scheele, The International Badminton Federation Handbook for 1971 (Canterbury, Kent, England: J. A. Jennings Ltd., 1971) 45.
- "Danish National Championships", Badminton USA, May 1971, 23.