Clarke, who started in the role on Wednesday (1 February), has been brought in to grow the group's comms and marketing brand Only Marketing across specialist industry sectors including health, retail and technology, the agency said.
Her appointment follows that of former Saatchi & Saatchi leader Kevin Roberts, who was announced as Beattie Group chairman in January.
Roberts' appointment was steeped in controversy, following comments he made last summer about gender diversity, which led to his resignation from the ad agency.
Clarke will work alongside Roberts, group CEO Laurna Woods and company president Gordon Beattie, and is "actively working to identify additional team members to help her achieve her ambitious growth ambitions," a spokesperson told PRWeek.
Prior to taking up the role as chair of the PRCA in 2012, she was group business development director at Hunstworth from 2003-2011. Before that, she was president of Weber Shandwick's Asia Pacific business from 2000-2002.
Clarke was also president of the CIPR in 2000 and founded Alison Clarke Communications in 2015.
Beattie has eight offices in the UK, and opened a business in Canada in June last year. It trades under three headline brands - PR and creative comms brand Beattie, student recruitment brand 11ten and its specialist brands under the Only umbrella.