  We prove that the only Calabi--Yau projective manifolds which bear
holomorphic Cartan geometries are precisely the abelian varieties. (Nous
d\'emontrons que les seules vari\'et\'es projectives de Calabi--Yau qui
poss\`edent des g\'eom\'etrie holomorphes de Cartan sont les vari\'et\'es
ab\'eliennes.)
