Oleh Ivanovych Ivashchenko () is a Ukrainian military officer and lieutenant general who has served as the head of the Main Directorate of Intelligence of the Ministry of Defense of Ukraine since 2 January 2026, replacing Kyrylo Budanov. Before that, he was the head of the Foreign Intelligence Service from 26 March 2024.
As of October 2017, in the rank of Major General, he served as the First Deputy Chief of the Defence Intelligence of Ukraine, Deputy Chief of the General Staff of the Armed Forces of Ukraine for Intelligence.
Since 2021, he has simultaneously served as Assistant Commander-in-Chief of the Armed Forces of Ukraine.
He performed these duties until 26 March 2024, when he was appointed Head of the Foreign Intelligence Service of Ukraine by President Volodymyr Zelenskyy.
On 2 January 2026, Zelenskyy announced that Ivashchenko would head the Main Directorate of Intelligence of the Ministry of Defense of Ukraine, replacing Kyrylo Budanov, who was appointed Head of the Office of the President of Ukraine.