Mennell joins Shakespeares' senior management team to work with partners and staff across the UK on leadership and training, alongside recruiting and developing people.
A fellow of the CIPD, he has held senior HR positions in the UK and internationally, including at Dow Jones in Asia Pacific, Dubai World in the United Arab Emirates and more recently, CPA Global, based in Jersey, Channel Islands.
Commenting on his new role, Mennell said: "I am looking forward to being a part of such a creative and growing organisation during such challenging times."