The pair will head the Council in 2020 following an election among council members.
The Council provides a formal mechanism to consult with practitioners on industry issues. The PRCA said it acts as a think-tank for the industry, informing the PRCA's strategic priorities, and producing commentary, advice, and best-practice guidance.
Francis is a founder member of Campaign Collective and chair of the PRCA Charity and Not For Profit Group.
"Demonstrating our social impact will improve recruitment and retention, ensure we are talking the language of board rooms and procurement teams and show to the public that we are a globally aware, responsible profession."
"As part of the social impact agenda, we will be encouraging PR and communications agencies to ‘buy social’ from social enterprises in 2020," said Francis.
The former Claremont director co-founded Campaign Collective in 2016 to provide affordable comms advice to charities and not-for-profit organisations, saying at the time that the agency itself is a social enterprise that will reinvest profits into the third sector.
Herd, managing director at PR agency Five in a Boat, said: "Placing our members at the heart of change and driving forward the industry in a positive way will be key for me."
PRCA director general Francis Ingham thanked the previous post holders, Amanda Coleman and Jessica Ozdemir, for their "tireless work" over the last year.
"Congratulations to both Simon and Julia for their election victories. Both had strong manifestos, and I’m sure they’ll drive the Council’s agenda and impact forward in 2020," he added.