Born into a family of musicians, Mäkelä's father is the violinist Sami Mäkelä, and his mother is the pianist Taru Myöhänen-Mäkela. His grandfather, Tapio Myöhänen, is a violinist and violist. His younger sister Ellen Mäkelä is a dancer with the Finnish National Ballet. Mäkelä studied conducting at the Sibelius Academy with Jorma Panula and violoncello with Marko Ylönen, Timo Hanhinen and Hannu Kiiski. He became interested in conducting at age 12, when he sang in the choir of the Finnish National Opera. He has been a soloist with Finnish orchestras such as the Lahti Symphony Orchestra, the Kuopio Symphony Orchestra and the Jyväskylä Sinfonia. He has performed at Finnish music festivals such as the Kuhmo Chamber Music Festival and the Naantali Music Festival. He plays a cello by Giovanni Grancino from 1698. In September 2017, Mäkelä first guest-conducted the Swedish Radio Symphony Orchestra. On the basis of this appearance, in December 2017, the orchestra announced the appointment of Mäkelä as its next principal guest conductor, effective with the 2018–2019 season, with an initial contract of 3 years. Mäkelä is the youngest-ever appointment to a titled conductor post with the orchestra. Since February 2018, Mäkelä has been artistic director of the Turku Music Festival. He also has an artist-in-association post with the Tapiola Sinfonietta. He has worked on musical projects with his partner, the cellist Senja Rummukainen. Rummukainen and Mäkelä were respectively the 1st and 2nd prize winners in the 12th Turku National Cello Competition. In May 2018, Mäkelä first guest-conducted the Oslo Philharmonic. On the basis of this appearance, in October 2018, the orchestra announced the appointment of Mäkelä as its next chief conductor, effective with the 2020–2021 season, with an initial contract of 3 seasons. This appointment marks the first chief conductorship for Mäkelä. In May 2020, the orchestra announced an extension of Mäkelä's initial contract with the Oslo Philharmonic for an additional 4 seasons, unusual in its timing before the official start of his tenure with the orchestra. In June 2019, Mäkelä first guest-conducted the Orchestre de Paris. In June 2020, the Orchestre de Paris announced the appointment of Mäkelä as its next music director, effective with the 2022–2023 season, with an initial contract of 5 seasons. He is to hold the post of musical advisor for the two prior seasons, from 2020 to 2022.
