TEL AVIV—Prime Minister Benjamin Netanyahu of Israel was indicted on corruption charges, posing a heightened threat to his personal and political future and deepening uncertainty as the country hurtles toward an unprecedented third election in a year.

Attorney General Avichai Mandelblit said on Thursday that Mr. Netanyahu faces charges of bribery, fraud and breach of trust in connection with three corruption probes, marking the first time a sitting Israeli leader has been indicted.

Mr....