John Gideon Haskell (February 5, 1832 – November 25, 1907) was an architect who designed portions of the Kansas State Capitol and other public buildings in the state.

His father moved to Lawrence, Kansas in 1854 with the New England Emigrant Aid Company while Haskell was attending Brown University and had an architect job in Boston.

After his father died in 1857, he moved to Kansas where he lived for the rest of his life.

[1][2] He joined the Union army during the American Civil War.

After the war he was named official state architect and as such finished the work on the Kansas State Capitol.