KRI Oswald Siahaan (354) is an Ahmad Yani-class frigate operated by the Indonesian Navy. Prior to her service in the Indonesian Navy, she served in the Royal Netherlands Navy as Van Speijk-class frigate HNLMS Van Nes (F805).

The Ahmad Yani class of six general-purpose frigates were acquired by the Indonesian Navy in the 1980s. They were originally built in the Netherlands for the Royal Netherlands Navy as the Van Speijk class which were licence-built versions of the British Leander class.