Originating in New Zealand in 2008, Blue September aims to encourage men and their families to ''face up" to the varieties of cancer that afflict men.
The campaign is also celebrated in Australia and the USA, and launched last year in the UK and Ireland.
Channel 5 reports Fletcher is set to play a gig at Shepherd's Bush Walkabout on September 27 in promotion of the cause, with all profits going to Blue September UK.
Fletcher will be supported on the date by London-based wedding and party band Lucas.
The first 100 RSVPs on Facebook or via email for the event will also be offered an opportunity to meet and greet with Fletcher after the show.
The popular actor tours the UK with his band The Waiting Room each year, and has claimed that interactions with UK Neighbours fans have been "some of the happiest of my life".