2033 Basilea, provisional designation 1973 CA, is a stony asteroid from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 6 February 1973, by astronomer Paul Wild at the Zimmerwald Observatory near Bern, Switzerland. The asteroid was named for the Swiss city of Basel. It came to perihelion in November 2025 and opposition on 23 January 2026 at apparent magnitude 15 in the constellation of Cancer.