Niilo Mäenpää

Hämeenlinna

Mäenpää started his senior career with the club, making his first competitive appearance on 23 May 2014 in a 1–0 home victory in the league over Tampereen-Viipurin Ilves-Kissat. He was subbed on for Juho Saarinen in the 68th minute.

Haka

In January 2015, Mäenpää moved to Ykkönen club FC Haka. He made his league debut for the club on 2 May 2015, playing all ninety minutes in a 2–2 away draw with JJK. He scored his first competitive goal for the club on 2 August 2015 in a 4–3 away victory in the league over MP. His goal, scored in the 69th minute, made the score 4–1 to Haka.

Inter Turku

In November 2017, Mäenpää moved to Veikkausliiga club Inter Turku, arriving alongside Mikko Kuningas. He made his league debut for the club on 7 April 2018 in a 2–0 away defeat to VPS, playing 63 minutes before being subbed off, to be replaced by Arttu Hoskonen.

IFK Mariehamn

On 28 November 2019 it was confirmed, that Mäenpää would join IFK Mariehamn from the 2020 season, signing a deal until the end of 2021.

Warta Poznań

On 22 December 2021, Mäenpää penned a two-and-a-half-year deal with Ekstraklasa club Warta Poznań, effective from 1 January 2022. He was released by the club at the end of the 2023–24 season.

Halmstad

On 15 July 2024, Swedish club Halmstad announced the signing of Mäenpää. He scored his first Allsvenskan goal on 19 October, in a 3–1 home win against Sirius.

Club

As of 13 May 2025

International

As of match played on 7 June 2024

Mäenpää's twin brother Aapo is also a professional footballer, playing for Ilves. The two played together in their early years at Hämeenlinna and Haka, before reuniting at Mariehamm beginning in 2020.

Inter Turku

Finnish Cup: 2017–18