The 158th Separate Mechanized Brigade (Ukrainian: 158 окрема піхотна бригада, romanized: 158 okrema pihotna bryhada) is a formation of the Ukrainian Ground Forces formed in 2024.

[1] The brigade was part of the creation and expansion of nine other brigades in the Ukrainian Ground Forces, announced by then Ground Forces' commander Oleksandr Pavliuk, in response to the Russian invasion of Ukraine.

[1] The brigade was formed after a Ukrainian mobilization law came into force, seeing the draft age being lowered from 27 to 25 and placing penalties for those avoiding conscription.

[2] In an interview with The Economist published in an article on 10 May 2024, Oleksandr Pavliuk, then commander of the Ukrainian Ground Forces, stated that Ukraine planned to create 10 new brigades in anticipation of a Russian offensive, and that some of them could be stationed in Kyiv to defend the city.

[4] On 16 July 2024, the Chernihiv Regional State Administration publicized a video calling for individuals to join the brigade.