An electrical circuit breaker with overvoltage protection includes a pair of connection terminals, a main semiconductor switch including at least one semiconductor component and a pair of separable contacts forming a disconnector connected in series with the main semiconductor switch between the connection terminals. The electrical circuit breaker also includes a first protection system connected in parallel with the main switch, the first protection system including a first protection device including a varistor and a first switch connected in series with the first protection device. The electrical circuit breaker further includes a second protection system, connected in parallel with the first protection system and said the main semiconductor switch, the second protection system including a second protection device including a transient voltage suppression diode.