Carl Wilhelm Borchardt (22 February, 1817 - 27 June, 1880) was a German mathematician.

Borchardt was born in Berlin, where he studied under Dirichlet until 1839, when he left for Königsberg.

He did research in the area of arithmetic-geometric mean, continuing work by Gauss and Lagrange. He generalised the results of Kummer diagonalising symmetric matrices, using determinants and Sturm functions .

He died in Rudersdorf , Germany.