Ippei Kojima (小島 一平, Kojima Ippei, 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).

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.