Murai (written: 村井) is a Japanese surname. Notable people with the surname include:
Hideo Murai (1958–1995), member of the Aum Shinrikyo cult
Jin Murai (born 1937), Governor of Nagano Prefecture
Jun Murai (born 1955), Japanese computer scientist
Kazusa Murai (born 1975), Japanese voice actress
Katsuyuki Murai (born 1969), Japanese actor
Kenjirō Murai, member of Cali Gari
Kunio Murai (born 1944), Japanese actor and voice actor
Shinji Murai (born 1979), Japanese football player
Taiki Murai (born 1993), Japanese footballer
Muneaki Murai (born 1973), Japanese politician
Yoshihiro Murai (born 1960), Governor of Miyagi Prefecture
Murai Sadakatsu (1528–1582), Japanese samurai
Murai Shimako (born 1928), Japanese playwright