Growing up in Jyvaskyla, Finland the basketball path is a bit different than in America. Markkanen played his junior years on a local team in HoNsU. In 2014, he transitioned to HBA-Marsky in the Finnish second-tier league. He played here until he left his native land for America to take his basketball career to the next level. 

The Finnish star verbally committed to the Arizona Wildcats on October 17, 2015. He later signed his National Letter of Intent to Arizona on November 11. Coming into the league, he was widely considered a one-and-done college player. Coming into Arizona, he was the first person since Mike Bibby to don the No. 10 jersey. This gave Lauri big shoes to fill, and the 7-footer ended up filling those shoes just fine.

Markkanen enjoyed his collegiate career-high on January 12 against in-state rival, Arizona State. He poured in 30 points against their in-state foe on that night. Following a great season, he was selected for Third-Team All-American, First-Team all Pac-12, and the Pac-12 All-Freshman team. In addition, he was a top 15 finalist for the John R. Wooden Award. In his sole season as a Wildcat, Markkanen averaged 15.6 points, 7.2 rebounds, and 0.9 assists per game. Following that year, he decided to declare for the 2017 NBA Draft.

Lauri Markkanen was drafted 7th Overall by the Minnesota Timberwolves in the 2017 NBA draft. On draft night, he was involved in a trade that sent him to Chicago. The blockbuster trade sent Zach Lavine, Kris Dunn, and Lauri Markkaenen to the Chicago Bulls, in return for Jimmy Butler and the rights to Justin Patton for the Minnesota Timberwolves. Lauri officially signed with the Chicago Bulls on July 5, 2017. 

In his NBA debut on October 19, Markkanen provided excitement for Chicago. After fans were highly upset about losing Jimmy Butler, Markkanen stepped up to the plate right away. In his debut, Lauri poured in 17 points. Following that, he set an NBA record for the most 3-pointers in the first three games of an NBA career with 10. His first 30-point game, and then career-high, came against the New York Knicks. On December 30, 2017, Markkanen dropped 33 points, due to the likes of eight three-pointers. This one great game of many in his rookie campaign helped Markkanen earn his spot on the NBA All-Rookie First Team. 

In his second season, 2018-2019, Markkanen, unfortunately, missed the first 23 games of the season due to injury. Following his return, Lauri posted his career-high in rebounds against the Brooklyn Nets on January 28, with 19 rebounds. Not too long after that, Markkanen poured in 35 points in a win over the Boston Celtics, setting his new career-high. Unfortunately again, on March 28, Lauri was ruled out for the rest of the season due to injury. He played 52 total games in 2018-19 and managed to average 18.7 points and 9 rebounds per game.

In his first game of the 2019-20 season, Markkanen came back with a vengeance. He played like he had something to prove, which to most, he certainly did. Markkanen tied his career-high with 35 points and added 17 rebounds to go along with it. This was the most points scored by a Chicago Bull on opening day since Michael Jordan. Markkanen has again missed a large portion of this season due to injury.