Olli Erkki Lehto was a Finnish mathematician, specializing in geometric function theory, and a chancellor of the University of Helsinki.

The University of Helsinki is a public university in Helsinki, Finland. The university was founded in Turku in 1640 as the Royal Academy of Åbo under the Swedish Empire, and moved to Helsinki in 1828 under the sponsorship of Tsar Alexander I. The University of Helsinki is the oldest and largest university in Finland with the widest range of disciplines available. In 2020, around 31,600 students were enrolled in the degree programs of the university spread across 11 faculties and 11 research institutes.