Small will be replaced by the company’s finance director, Neil Greenhalgh, who joined in 2004.
The sportswear retailer said Greenhalgh has been heavily involved in all aspects of its international expansion over the past 14 years and has been increasingly taking on many CFO tasks in recent years in anticipation of an orderly succession.
Chairman Peter Cowgill said: "I would like to thank Brian for his valuable contribution and support over the last 15 years at JD and we wish him well in his retirement. I would also like to welcome Neil to the board of JD.
"The board is delighted that a planned succession has been achieved. Neil has already made a substantial contribution to JD and his promotion to the board will enable him to contribute still further.''