The 143rd Separate Mechanized Brigade () is a unit of the 15th Army Corps as part of the Ground Forces of Ukraine based in Ladynka. Originally the unit was a reserve rifle brigade, it was reformed into an infantry brigade later in 2023 and into a mechanized brigade in December 2024.
The 143rd Mechanized Brigade was formed on 15 February 2023, as part of an expansion of the Ukrainian Army reserve, bringing together rifle battalions recruited from various Ukrainian regions subordinate to Operational Command North.
The brigade first saw combat in March 2024, when it was deployed to the village of Terny in the Lyman sector in front of the Svatove-Kreminna line. In August 2024, it was transferred to Kharkiv Oblast to defend the town of Vovchansk.
In March 2024, the brigade's 468th battalion was active in the Chasiv Yar sector. In April 2024, the battalion fought in outskirts of the village of Kalynivka, Bakhmut Raion, Donetsk Oblast.
As of 2024 the brigade's structure is as follows: