He was born on July 22, 1936 in Cameron, Texas. His Father, Drayton McLane, Sr., owned a wholesale grocery distribution center. At age nine, the young McLane went to work for his father's Business that had been established by his grandfather, Robert McLane, in 1894. His grandfather came from Abbeville, S.C., to Cameron, Texas, in the late 1800s and worked as a farm laborer until about 1885, when he was able to buy and build a small Retail grocery and in 1894 went into the wholesale grocery Business in a small way. McLane Jr. spent most Saturdays and summers during his teen years sweeping floors and learning various aspects of the wholesale grocery Business. He graduated from C.H. Yoe High School in Cameron in 1954.

He earned his undergraduate degree at Baylor University in 1958 and his Master of Business Administration (MBA) degree in marketing at Michigan State University in 1959. After graduation, McLane returned home and went to work for his Father. For the first 18 months, he worked the second (night) shift loading trucks. Three years later he moved into management as vice President of purchasing. He then served 14 years as general manager of operations. He became President and CEO of McLane Company in 1978 and chairman in 1992.

As President and CEO of McLane Company from 1965 to 1994, he added 16 distribution facilities across the US. During that time the company experienced an average yearly sales growth of 30%. During those years, Drayton Jr. served as President of the Texas Wholesale Grocers Association (1970–1971) and Chairman of the National American Wholesale Grocers Association (1986–1988).

He sold the family Business to tennis partner Sam Walton for cash and Wal-Mart shares in 1990. He invested much of the profits in pro baseball's Houston Astros. He continued as chairman of McLane Co. and was named vice chairman of Wal-Mart Corporation. In 1993, he resigned both of these positions in order to devote his full-time as Chairman of McLane Group, which is a holding company founded in 1992.

From the time he purchased the team in 1993 to 2005, the Astros ranked fifth in the Majors and second in the National League in winning percentage (.543), but never won a World Series. The Astros, originally the Colt 45's, were founded in 1962. They won their first World Series in 2017 (2017 World Series).

In 2005, Scott and White Memorial Hospital in Temple honored Drayton and his wife by creating the Elizabeth and Drayton McLane Jr. Chair in Health and Wellness, a new endowed chair that is a joint appointment between the hospital and the Texas A&M University Health Science Center College of Medicine.

Michigan State University Activities and Philanthropy: By the spring of 2009, the McLane family will have brought “new life” to its baseball facility through a $4 million commitment to enhance one of the most pristine environments in all of intercollegiate athletics. On September 12, 2008, the MSU Board of Trustees voted unanimously to approve the naming of Drayton McLane Baseball Stadium at John H. Kobs Field.

McLane announced in November 21, 2010, that the Astros franchise was for sale. A recent regional television deal puts the Astros on a similar footing as other National League teams, and should help with the income side of this transaction. McLane said the sale was for "family" reasons, and he was joined in the announcement by his two adult sons, Drayton III and Denton. It was sold on Nov 17th, 2011 for $610 million. Since the sale, Drayton has been sued by the purchaser, Jim Crane, for breach of contract, fraud, negligent misrepresentation or omission, and civil conspiracy.

Baylor University announced in December 2013 that it would name its new football stadium "McLane Stadium" after "one of the most distinguished and generous alumni families in Baylor University history."

His past civic duties include: Chairman of Board of Trustees, Baylor Scott & White Healthcare; Chairman Scott and White Health care Board of Trustees; VP of Executive Board—Boy Scouts of America; Chairman—United Way of the Texas Gulf Coast’s Pacesetter Campaign; Member—Children’s Miracle Network National Board of Governors; Chairman of the Board—Children’s Miracle Network; Member—Texas State Board of Mental Health and Mental Retardation; Chairman of Board of Trustees—Baylor University; Chairman of Board of Regents—Baylor University; Member of the Greater Houston Partnership; Chairman of Temple (Texas) Chamber of Commerce; Trustee—South Texas College of Law. In the religious community of Temple, Texas, he has served as the chairman of the Deacon Board of First Baptist Church.

Up until 2017, the Astros 2005 season was the most successful season on the field for the Houston franchise. Winning the National League Pennant to advance to the World Series, Houston hosted the first World Series game ever played in the State of Texas. However, the Astros, who had rallied from a losing record earlier in the season, were swept by the Chicago White Sox in four games, granting the White Sox its first championship in 88 years. The Astros sport the fourth longest World Series drought in MLB, with no World Series in 53 years.