Donald L. Dell (born June 17, 1938) is an American sports attorney, writer, commentator, and former tennis player. Dell was the first sports agent in professional tennis, and represented Arthur Ashe, Stan Smith, Jimmy Connors, and Ivan Lendl during the golden age of pro tennis (1975 to 1985). He was also the founder of Professional Services (ProServ), one of the nation's first sports marketing firms established in 1970. Dell is considered one of the fathers of sports marketing and the sports agent business along with IMG's Mark McCormack. Dell co-founded the Association of Tennis Professionals (ATP) in 1972 with Jack Kramer and Cliff Drysdale. Clients of ProServ dominated the leadership roles of the ATP in its formative years. ProServ expanded into basketball, and Dell signed Patrick Ewing, Michael Jordan, and other top NBA players. He wrote his first book, Minding Other People’s Business in 1989 about how to recruit, manage, market, and keep client athletes, and a second book in 2009, Never Make the First Offer. Dell negotiated two of the most successful shoe deals in all of sports: Michael Jordan’s Air Jordan line with Nike and the Stan Smith shoe with Adidas. Donald has a younger brother, Dick, who worked at ProServ and went to the University of Michigan and was Big Ten Tennis Champion.