Michael Harris Sr. and LaTaucha Harris are the parents of Michael Harris II.[1][2][3] His mother was a special education teacher for the Fulton County School System[2].[4] and his dad was an Alcorn State baseball player in college.[5][6] Mikaylah is his sister.[5] Harris was raised close to Turner Field and has always desired to be a player for the Atlanta Braves.Harris was born in DeKalb and Henry counties[7] and raised in Stockbridge, Georgia, where he later attended Stockbridge High School.[8] In summer leagues as a high school student, he was trained by family friend Marquis Grissom, and in the off-seasons, Grissom provided him with additional instruction.

In the third round of the 2019 Major League Baseball draft, he was selected by the Atlanta Braves.[9] In exchange for a $548,000 bonus, he signed with the Braves, abandoning his plans to play veterinary medicine and his pledge to play collegiate baseball at Texas Tech University.[13] Harris had only been recruited as a pitcher by the Louisiana State Tigers baseball club before he had given Texas Tech any thought.

That year, Harris was promoted to the Rome Braves after beginning his professional career with the Gulf Coast Braves.[14] He hit.277/.344/.393 with two home runs and 27 runs batted in over 53 games between the two teams.
He did not play for a team because the 2020 Minor League Baseball season was cancelled due to COVID-19.[15] The Braves invited him to spring training in 2021.[16] He played for the Rome Braves during the 2021 season, when he slashed.294/.362/.436 with seven home runs, 64 RBI, and 27 stolen bases.[17] He was chosen to participate in the All-Star Futures Game in June.