SC 42

SC 42 may refer to:


 * Convoy SC 42, a World War II transatlantic convoy of merchant ships
 * USS SC-42, a United States Navy submarine chaser commissioned in 1918 and sold in 1921
 * Scandium-42 (Sc-42 or 42Sc), an isotope of scandium
 * South Carolina Highway 42 (1920s), a former state highway from Sumter to Bishopville
 * South Carolina Highway 42 (1930s–1940s), a former state highway from northeast of Cope to Orangeburg