The role, which is the charity's first designated PRO role, has been created in a bid to boost Crusaid's profile among businesses and the City.
According to Bates, previous PR efforts were carried out 'as an add-on' by events and appeals teams.
Bates, who reports directly to CEO Edward Lord, said that he will also be working with Lord on a strategic review of communications, as part of an overhaul of all departments.
This is expected to lead to a branding review later in the year. Bates said the charity will probably hire an outside firm to carry out this review.
Within months Bates, together with head of research Simon Duckworth, is to launch the charity's first The City Cares campaign, which will target city firms for donations.
There will also be a PR push to promote the charity's Walk for Life fundraiser, which takes place on 22 June.
The charity's main areas of work are its hardship fund, which last year handed out £800,000 in grants to those with HIV and Aids living in poverty, and its Crusaid Hannam Clinic in Guguletu, South Africa.
The Stop Aids Campaign is a coalition of 26 UK organisations, set up to lobby the Government over issues related to Aids and HIV.
Campaign chairman Derek Bodell said that communications is currently undergoing a 'strategic review', which ends in two months time. Bodell added that the outcome of the review is likely to lead to the campaign targeting one specific issue relating to HIV/Aids. A favoured option is the level of access to treatment.
Before joining the Stop Aids campaign two years ago, Bates worked with PR firm Marketforce Communications, specialising in B2B communications.