The previous incumbent was Quill Communications.
The appointment of Polhill marks a move into consumer PR for Clerical Medical, the UK's fifth largest financial services company.
Polhill founding director Terry Hepplewhite said the Clerical Medical brand enjoyed significantly better recognition among independent financial advisers tasked with selling their products than among consumers.
He said Polhill's main task would be to increase consumer brand recognition and stress Clerical Medical's 'quality of service'. Polhill will also provide support and back-up to the company's in-house team.
Last year Clerical Medical appointed a team of three to broaden the firm's media relations from trade work to large provincial and national media relations.