The group approached Threepipe following a client recommendation.
Threepipe has been briefed to plan a targeted PR campaign for Parkrun aimed at raising its profile among commercial and public sector partners.
The agency will also work with the group to determine how best to grow in the future by defining its values, position and key messages.
Tom Williams, Parkrun UK MD, said: "As Parkrun continues to grow in the UK, with more and more entrants and runs every week, it was important for us to define exactly what the Parkrun brand is for our community as well as potential partners."