Garden centre director Chris Francis said: "Dan will be a great asset to Hillier following the recent refurbishment of our centres and the expansion of our offer.
"Dan joins us ahead of some exciting projects such as the launch of the new restaurant in our centre in Newbury, and will be a real asset in driving performance and further improvements".
Williams said: "I’m excited about this opportunity. Most recently I have worked for Catering Academy – a vibrant independent catering company - driving innovation across a number of business sectors and I also have previous experience developing the food and beverage offer within a national group of garden centres.
"I look forward to bringing my passion for great customer service and quality food to Hillier Garden Centres and am committed to continuing to enhance the restaurant offer for our customers."