Listeners have until 21 June to submit an application, through www.smoothradio.com, to become one of the six regional Smooth ambassadors to represent the radio network in the ad, and at key events during the year.
A spokesman for Smooth Radio said it was looking for listeners from around the country who represent Smooth Radio's outlook on life and share its love of life and music.
Entrants need to upload a photograph and create an online profile. The listener should use the profile to express their character and love of life, and reveal exciting things they have done in the past.
To generate interest, Smooth Radio will visit five shopping centres across the UK and give listeners and shoppers a chance to share their stories, meet Smooth radio presenters, have a free makeover, and have their photos taken professionally.
Helen Dickinson, group marketing manager at GMG Radio, said: "We know from our research how passionate the listeners are about Smooth Radio. This campaign harnesses the power of these advocates to introduce new listeners to the brand in an exciting and engaging manner."
The marketing activity has been brokered by Euro RSCG KLP.
A panel of Smooth Radio presenters and celebrities will choose the final six ambassadors from the shortlisted finalists, and full details of the ad campaign featuring The Smooth Radio Ambassadors will be announced later in the summer.
In March, GMG Radio appointed full service marketing and communications agency Euro RSCG KLP to the ad account for the Smooth Radio brand, following a pitch against Krow, CST and Hurrell Moseley Dawson & Grimmer.