The Norwegian took permanent charge in March 2018 after a highly-successful three months as interim boss but departs with United seventh in the Premier League standings, 12 points behind leaders Chelsea having lost five of their last seven matches.
While United begin their search for a successor, first-team coach Michael Carrick has been put in temporary charge and will oversee United's Champions League visit to Villarreal on Tuesday.
Solskjaer oversaw a huge summer outlay on signings that were meant to propel United to genuine title challengers after their runner-up finish in 2020/21.
Big money was laid out to lure Jadon Sancho and Raphael Varane, while Cristiano Ronaldo's return was supposed to pick up where it left off more than a decade ago.
We take a look back on Solskjaer's 14 signings as United manager and rate whether they have been a hit or miss. Check out the photo gallery above.