The competition, devised by Euro RSCG London, encourages consumers to upload a clip of themselves singing to its Facebook page, with a brief description of why they should become the voice of Strepsils.
They can share their entry with friends and the voice with the most likes on Facebook will get the chance to sing on the Strepsils radio ad this summer.
In April this year, Reckitt Benckiser announced that marketer Rakesh Kapoor would be taking over from chief executive Bart Becht when he retires in September.