Oleksandr Oleksandrovych Sak (Ukrainian: Олександр Олександрович Сак) is a Ukrainian soldier, lieutenant colonel,^[2] and the former commander of the 47th Mechanized Brigade of the Armed Forces of Ukraine until 16 September 2023 when he was replaced by Colonel Oleksandr Pavlii.^[3]

In 2023, he was included in Forbes 30 Under 30: Creators of the Future rating.^[4]

Graduated from the Zakarpattia Regional Boarding Lyceum with enhanced military and physical training, Faculty of Combat Use of Troops of the Hetman Petro Sahaidachnyi National Army Academy (2015).^[1]

After graduation, he began his service in the 93rd Mechanized Brigade "Kholodnyi Yar".^[1]

Participated in combat in the ATO/JFO area. In the summer of 2015, he became a company commander, and in 2019 — the commander of the 3rd Battalion. He was wounded three times.^[1]

During the full-scale Russian invasion, he was the commander of a mechanized battalion that engaged in combat with the enemy's battalion tactical group and won thanks to a rational approach to combat and non-standard tactics.^[5]

In 2022, he was appointed commander of the newly created 47th Mechanized Brigade.^[6][7]

On 16 September 2023, he was sacked and replaced Colonel Oleksandr Pavlii who had previously commanded the 112th Separate Brigade of the Territorial Defence Forces of the city of Kyiv since 2022.^[3][8]

On 25 November 2024, he was appointed as the new commander of the 53rd Mechanized Brigade.^{[citation needed]}

• Order of Bohdan Khmelnytskyi, 1st class (8 August 2022)^[9]
• Order of Bohdan Khmelnytskyi, 2nd class (7 March 2022)^[10]
• Order of Bohdan Khmelnytskyi, 3rd class (4 February 2016)^[11]
• Order of the People's Hero of Ukraine^[1]
• Medal "Defender of the Fatherland" (27 October 2016)^[12]