Murai (written: 村井) is a Japanese surname. Notable people with the surname include:
Hideo Murai (1958–1995), member of the Aum Shinrikyo cultJin Murai (born 1937), Governor of Nagano PrefectureJun Murai (born 1955), Japanese computer scientistKazusa Murai (born 1975), Japanese voice actressKatsuyuki Murai (born 1969), Japanese actorKenjirō Murai, member of Cali GariKunio Murai (born 1944), Japanese actor and voice actorShinji Murai (born 1979), Japanese football playerTaiki Murai (born 1993), Japanese footballerMuneaki Murai (born 1973), Japanese politicianYoshihiro Murai (born 1960), Governor of Miyagi PrefectureMurai Sadakatsu (1528–1582), Japanese samuraiMurai Shimako (born 1928), Japanese playwright