Jones joins the agency from OgilvyOne, where she was the managing partner running its Department of Health account.
Reporting to the chief executive, Martin Nieri, Jones will oversee the BMW, Hibu and Investec accounts, as well as play a key role in business development.
Jones joins Mark Davison and Paul Vallois as managing partners at Partners Andrews Aldridge.
She will sit with them on the agency board alongside other members of the senior team including Steve Aldridge, the creative partner and chairman; Paul Snoxell, the creative director; and Dan Northover, the digital design director.
Before joining OgilvyOne, Jones was the client services director at Archibald Ingall Stretton from 2007 to 2010.
She has also worked at Rapier and Wunderman.
Nieri said: "Polly is a great fit with PAA. She has a really good agency heritage and brings with her creative thinking and rigour from agencies that we have always respected."