Toshihide Maskawa (or Masukawa) (益川 敏英, Masukawa Toshihide, born February 7, 1940 in Nagoya, Japan) is a Japanese theoretical physicist known for his work on CP-violation who was awarded one quarter of the 2008 Nobel Prize in Physics "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."