The hire follows a four-way competitive pitch. The account was previously held by Zeitgeist, which did not re-pitch.
Shine’s brief is to target the lifestyle press, digital influencers and social media to raise the festival’s profile in the UK.
The festival, organised by Alter Art, runs from 1 to 4 July and includes high-profile acts including Drake, Kasabian, The Libertines and Mumford & Sons.
A spokesperson for Alter Art said: "We have worked with some of the Shine team before and we believe its insight-led creative strategy and superior media contacts will be pivotal in bringing further momentum to our business and connect further with music lovers across the UK."
Shine MD Lawrence Collis said: "Shine Communications has a rich history of working in the music and entertainment space and Open’er allows us to continue that tradition and provide our teams with an exciting client."