The 1958 1000 km Buenos Aires took place on 26 January, on the Autódromo Municipal-Avenida Paz,. It was the fifth running of the race, and once again, it was opening round of the F.I.A. World Sports Car Championship. For this event, it returned to the Autódromo, after having a one-off race at the Circuito de la Costanera Norte, however its layout was not generally well received.

The 1958 World Sportscar Championship was a motor racing series for sportscars which ran from 26 January to 13 September 1958 and comprised six races in six countries. It was the sixth World Sportscar Championship.