It received generally positive reviews from critics and was selected as the Finnish entry for the Best Foreign Language Film at the 89th Academy Awards, but it was not nominated.

It's the year 1962: Olli Mäki (Jarkko Lahti) is a Finnish amateur-turned-professional boxer from the town of Kokkola who, while attending a wedding, becomes smitten with his friend Raija (Oona Airola).

The Happiest Day in the Life of Olli Mäki was the feature-length debut of director Juho Kuosmanen, who had previously directed short films as well as theatre and opera productions.

The website's consensus reads: "The Happiest Day in the Life of Olli Mäki sidesteps sports biopic clichés with a beautifully filmed, well-acted look at the balance between career fulfillment and personal happiness.

[5] Peter Bradshaw of The Guardian gave the film 4 out of 5 stars, and described it as "a gentle, shrewd, somehow mysterious love story, based on real life, beautifully photographed in luminous black-and-white and drawing inspiration from Scorsese and Truffaut.

"[7] David Rooney of The Hollywood Reporter called the film "a small marvel of impeccable craftsmanship", lauding its black and white cinematography and "faultless and unshowy" performances.

[8] Geoffrey Macnab of The Independent said Olli Mäki "rethinks and revitalises" the genre of boxing movies and also found it one of the year's most likeable films.