Charles C. Lauritsen was a Danish-born American physicist.
Lauritsen and his wife Sigrid and son Thomas emigrated to the United States in 1916. He received his PhD and became Professor of Physics at Caltech. He became friendly with colleague J. Robert Oppenheimer, who later recruited him for the Manhattan Project. During the war, he developed rocket weapons for the military.
He was involved in early Manhattan Project discussions on the MAUD Report. He worked at Los Alamos, helping to develop the non-nuclear "pumpkin bombs" used primarily for testing and training purposes. His son Thomas Lauritsen, also a physicist, also worked at Los Alamos on the project. After the war, he continued to teach at Caltech and consult for the government on weapons development. He conducted research on X-ray radiation therapy for cancer patients and helped establish the Kellogg Radiation Laboratory.