Steffisburg is a municipality in the administrative district of Thun in the Canton of Bern in Switzerland. On 1 January 2020 the former municipality of Schwendibach merged into the municipality of Steffisburg.

Steffisburg is first mentioned in 1133 as Stevensburc. The municipality was formerly known by its French name Steffisbourg.

The area around Steffisburg has been inhabited since the Neolithic era and remained occupied during the Bronze Age. Traces of a Roman site were discovered in Schwäbis.