ATHEISTS have begun an advertising campaign on Melbourne buses, proclaiming ''Atheism - celebrate reason'', the first time they have entered the fray in such a public way.

The signs are on the backs of 24 buses until March 29, when the number will rise to 40 and the advertisements will be included on the sides as well, according to Atheist Foundation of Australia president David Nicholls.

British atheists, including author Richard Dawkins, began advertising on buses last year, and now Melbourne is getting on board. Credit:Reuters

''This is the first time we have advertised in public in such a big way - it's a very significant move forward for atheists,'' Mr Nicholls said.

Everyone seems to be getting on board since British atheists began the trend late in 2008, irked that Christians seemed to have a monopoly on billboard advertising. It spread to atheists in Spain, then other parts of Europe and the US. New Zealand atheists hope to follow suit.