Tetsuyuki Morikawa (森川 テツユキ Morikawa Tetsuyuki; April 10, 1930 – September 10, 1999) was a Japanese serial killer who killed two of his ex-wife's relatives in Kumamoto, after having been released on parole for killing his mother-in-law in 1962. For the latter crimes, Morikawa was sentenced to death and subsequently executed in 1999.