Marketing Week has reported that Webb joined the company last week and it is understood that he will be the company's chief marketer.
Hamleys confirmed his appointment, but declined to give further details of his responsibilities.
Hartley left the company in August after two years, planning to undertake consultancy work.
At the time of her departure, the retailer confirmed that it was planning to make redundancies as part of a cost-cutting exercise, although Hamleys claimed that reports of up to 20 job losses in the marketing department were inaccurate.
Despite the restructure, the retailer is continuing with its international store opening plans. It is due to open stores in Dubai and Dublin and franchise stores are planned for Russia, China, India and Turkey.
A Hamleys spokeswoman said: "Webb is very new to the company and it is too early to comment on the role. We will announce our marketing roadmap for 2009 and our advertising strategies in the coming months."
Source: Marketing Week