Steve de Polo has been promoted to managing director of Byron following the departure of chief operating officer Nick Young.
Young is leaving the business after a year, with de Polo taking on some of his responsibilities. De Polo joined the hamburger chain as commercial and brand director from pub firm Ei Group two months ago.
A spokesperson for Byron said: "We are delighted to confirm that Steve de Polo has taken on a larger role within Byron as the company enters an exciting new period.
"Steve will take over some responsibilities from Nick Young, Byron's COO, who has decided to leave the business. We are sincerely grateful to Nick for all his work and we wish him the very best for the future.
"Byron's financial restructuring and CVA process is now complete and we have turned our attention to achieving operational excellence, evolving the Byron brand and continuing our journey to turn the UK into a nation of proper hamburger lovers."
Earlier this year Byron became the first high-profile casual dining brand to enter a CVA resulting in it exiting 19 loss-making restaurants, with rent reductions agreed on a further five sites.
In the company's financial results for the year to 25 June 2017 Byron reported a pre-tax loss of £55m. Byron's directors said "material uncertainty" caused by difficult conditions "may cast significant doubt over its ability to continue as a going concern".