Sankt Augustin (Ripuarian: Sank Aujustin) is a town in the Rhein-Sieg district in North Rhine-Westphalia, Germany.

The missionaries established the "Saint Augustine Monastery" near the current town centre in 1913.

The municipality of Sankt Augustin was established in 1969, and on September 6, 1977, Sankt Augustin acquired town privileges (German: Stadtrechte).

With over 59,000 inhabitants, it is the second-largest town in the Rhein-Sieg district.

[3] Sankt Augustin is twinned with:[4] and has a Community Climate Partnership with: