Friend will succeed Jim Donaldson when his term as chairman concludes in the Autumn of 2020.
She is responsible for Weber Shandwick’s network of offices across the UK, and has more than 20 years’ experience in the industry.
She has spearheaded marketing and communications campaigns some of the world’s leading brands.
Friend said: "We are living through a period of unprecedented change; politics, sustainability, diversity, technology. Our industry must continue to evolve at a rapid pace to engage audiences.
"I’m very much looking forward to working with the PRCA to fuel the change."
PRCA director general Francis Ingham said: "It’s a sign of the PRCA’s strength and size that someone of Rachel’s global standing will become our Chairman in 2020.
"In following Jim Donaldson, she will oversee the next phase of the PRCA’s story, as we build on our status as by far the world’s largest and most dynamic PR association."