Rafael Bombelli (baptized on 20 January 1526; died 1572) is an Italian mathematician.

Born in Bologna, he is the author of a treatise on algebra and is a central figure in the understanding of imaginary numbers.

He is the one who finally manages to settle the problem with imaginary numbers.

In his 1569 book, L'Algebra, Bombelli solves equations using the method of del Ferro/Tartaglia.

He introduces the representative symbols +i and -i and describes how they both worked.

The lunar crater Bombelli is named after him.