He joins from Towergate Insurance where he was interim chief executive, having joined in April 2012 as chief financial officer and will be earning £525,000 as a starting salary.
Prior to Towergate, he also held the chief finance position at Brit Insurance and was chief financial officer, latterly group financial controller at Zurich Financial Services.
Egan will also join the RSA board as executive director.
Group chief executive Stephen Hester said: “[Scott] will strengthen our team and bring excellent skills and in-depth knowledge and experience of the insurance industry. Scott’s appointment is another positive step in building a strong and valuable RSA.”Egan said he was looking forward to “cementing a bright future for the company.”