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.
Basilea orbits the Sun in the inner main-belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,212 days). Its orbit has an eccentricity of 0.11 and an inclination of 8° with respect to the ecliptic.
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 7.82 kilometers based on an absolute magnitude of 12.9.
This minor planet was named for the Swiss city of Basel, as well as for the Astronomical Institute of the University of Basel on the occasion of its 50th anniversary. The approved naming citation was published by the Minor Planet Center on 1 June 1980 (M.P.C. 5359).