Koike is a Japanese surname. Notable people with this surname include:
Akihiko Koike, a retired Japanese male race walkerAkiko Koike, a Japanese voice actressAkira Koike, a Japanese politicianAyame Koike, a Japanese actressEiko Koike, a Japanese idol and actressJunki Koike, a Japanese football playerKazuko Koike, a Japanese creative directorKazumori Koike, a Japanese sprint canoerKazuo Koike, a Japanese manga writer, novelist, and entrepreneurKensuke Koike, a Japanese contemporary visual artistMasaaki Koike, a Japanese baseball playerMasakatsu Koike, a Japanese politicianReizo Koike, a Japanese breaststroke swimmerRina Koike, a Japanese idol and actressRyohei Koike, a Japanese football playerShota Koike, a Japanese baseball catcherTakeshi Koike, a Japanese studio animator, illustrator, and film directorTeppei Koike, a Japanese actor and singerToshiki Koike, a Japanese football playerYui Koike, a Japanese gravure idol and actressYuki Koike, a Japanese football playerYuriko Koike, a Japanese politician