Harold Aidoo Fiifi (born 5 April 1996) is a Ghanaian-Finnish professional basketball player for BC Nokia of the Korisliiga.
Aidoo was born in Accra, Ghana but moved to Helsinki, Finland at age 5.
Aidoo started out his career at HBA-Marsky Helsinki where he played from 2012 to 2016. During the 2018–19 Korisliiga season, he played for Ura Basket. In 2019, Aidoo represented Joensuu's Kataja Basket and later joined the team's competitor Kobrat of the Korisliiga. With Kobrat, he averaged 9.0 points, 3.1 rebounds and 3.4 assists.
In 2020, he moved to CB Benicarlo in Spain on a one-year contract.
For the 2023–24 season, he returned to Finland and signed with BC Nokia.
Aidoo has been a member of Finland's national basketball team.