Samuel Poyntz Cochran, businessman, was born to John Carr and Samuella Tannehill (Dewees) Cochran on September 11, 1855, at Lexington, Kentucky. He attended elementary school in Cincinnati, Ohio, and high school in Covington, Kentucky, where he graduated as valedictorian of his class in 1873. Although he passed examinations that qualified him to serve as a public school principal, he never took a full-time position as either a principal or a teacher. Instead, he was an occasional substitute teacher, but devoted the majority of his time to the fire-insurance business, which he entered at Cincinnati as an inspector in 1873. In 1874 he joined the J. W. Cochran and Son Insurance Company in Lexington. In 1876 he returned to Covington, where he operated a branch of the company until 1881. Cochran was also deputy United States marshal for the Eastern District of Kentucky from 1878 until 1880. He moved across the Ohio River to Cincinnati for a brief period in 1881 and worked as an agent for the Lancashire and the Phoenix insurance companies.
That year he moved to Dallas, Texas, where the Phoenix Company employed him as an itinerant agent. After three years of traveling the state by stagecoach, Cochran joined the insurance firm of Dargan and Trezevant in Dallas. On January 1, 1884, he became a partner in this company, which four years later became Trezevant and Cochran. When the senior partner retired in 1914, Cochran became the head of the firm, which had become one of the largest independent insurance agencies in the Southwest and served as the representative for ten national companies. He remained in this position until his retirement.
Outside of his business interests, Cochran devoted much of his time to work as a Mason. He became a Freemason in 1880 and joined Dallas Lodge No. 760 upon his arrival. He accumulated many of the group's honors and held many of its elective offices, including that of grand master of Texas Masons. He was instrumental in organizing the Dallas Scottish Rite Cathedral, a home for aged Masons in Dallas, and the Texas Scottish Rite Hospital for Crippled Children. He was also president of the Texas Scottish Rite Educational Association, which raised funds for a women's dormitory at the University of Texas. For these and other activities a $25,000 bronze statue was erected in Cochran's honor on the lawn of the Scottish Rite Cathedral in Dallas in 1920.
Cochran served on the board of directors of a number of Dallas institutions, including the Mutual Building Association (which he served as president from October 14, 1889, until his death), the American Exchange Bank, the United States Bond Mortgage Company, and the State Fair of Texas. He was a regent of the University of Texas from 1921 to 1924. He served as president of the Texas Society of the Sons of the American Revolution, 1924–28, and vice president of the national organization, 1927–29.
On July 3, 1883, he married Sue Webb Higgins of Lexington, Kentucky. After she died, Cochran married Regina Urbish of Dallas, in 1934. He was a Democrat and a Christian Scientist. He died at his home in Dallas on February 11, 1936.