Frans Oort (born 17 July 1935) is a Dutch mathematician who specializes in algebraic geometry.

He received his doctorate in 1961 in Leiden from Willem Titus van Est [de] and Jaap Murre with thesis Reducible and Multiple Algebraic Curves,[1] but had previously studied under Jean-Pierre Serre in Paris and Aldo Andreotti in Pisa.

[citation needed] His doctoral students include Bas Edixhoven, Michiel Hazewinkel, Aise Johan de Jong, Hendrik Lenstra and Joseph Steenbrink.

[4] In 1962, Oort made a short contribution Multiple algebraic curves at the International Congress of Mathematicians in Stockholm, but was not an invited speaker.

[2] In July 2013, he gave a talk at the International Congress of Chinese Mathematicians in Taipei.