Mr Cooper, previously operations director, replaces Sean Lam, who recently took over from Rodney FitzGerald as chief executive of the company.
In other changes, Dominic Martin has been promoted to managing director, Walker Crips Wealth Management and Wendy Eastwood has been promoted to managing director, Walker Crips Pensions.
Mr Martin and Ms Eastwood were previously directors in the business areas they now lead. They take up their new responsibilities from interim head of York operations Nigel Skelton, who is stepping back to his previous role managing client relationships.
Don Formhals and Valentina Kang have been given expanded roles as part of the changes. Mr Formhals, formerly finance director for the firm’s York branch, will become finance & operations director for the office while Ms Kang’s quality assurance role will expand to quality assurance director.
Sean Lam, chief executive, Walker Crips, said: "It gives me great pride and pleasure to congratulate our talented team on their well-deserved promotions.
“I would like to thank our staff for their ongoing contribution to our success and I look forward to working with them as we embark upon our next stage of growth as a technology-driven financial services company.”