Leopold Eckler was born in Brno, in what is now Czechia, on March 3, 1898, to Alfred and Dorothea Eckler. Brno was then part of the Austro-Hungarian empire, and Eckler was raised in Vienna, where his father established a factory for the manufacture of souvenirs. He was graduated from the Imperial-Royal "Real" School (Oberrealschule) in 1916 and enrolled at the Charlottenburg Technical College to study chemistry before volunteering for the imperial army as an officer. He fought in Italy during World War I, and spent nine months after the Armistice as a prisoner of war there; after his release he resumed his studies at Charlottenburg, taking his chemistry degree in 1922 and his doctorate in 1925.

After briefly studying adhesives, Eckler joined the German firm Agfa in March 1924, where he was assigned as a unit chief at a film plant in Wolfen. In November 1928 he came to Ansco after its merger with Agfa, on what was supposed to be a temporary assignment to oversee the arrangement of the firm's casting department. He decided to stay, and in 1932 took charge of all Ansco manufacturing. He became a U.S. citizen in 1936.

In 1942 he and other executives were briefly suspended from their positions by the U.S. Treasury Department while the firm was removed from German control. More than 900 workers signed a petition urging his reinstatement, which came within several months.

Eckler left Ansco for Celanese Corporation in 1948, where he was in charge of the Plastics Division. He returned to Ansco in June 1955 as General Manager of Ansco Division, Vice-President of General Aniline & Film. He retired in 1963.

Eckler was active on various corporate and non-profit boards, including GAF, Bell & Howell, First City National Bank, the Sheraton-Binghamton Corporation, Broome County Chamber of Commerce, New Industries for Broome, the Valley Development Corporation, Broome County College Foundation, Binghamton General Hospital Foundation, Wilson Memorial Foundation, Binghamton Rotary, Binghamton Club, Binghamton Torch Club, and more. He also served as a trustee of Broome Community College, and was active in the Broome Heart Chapter, the Tuberculosis and Public Health Association, the Binghamton Boys Club, and the American Civic Association. Professionally he was involved with the American Chemical Society, the Photographic Society of America, the Society of Motion Picture Engineers, and the Chemists' Club of New York. His favorite hobby was hiking.

In his will, Eckler left an endowment of $1 million for scholarships at Broome Community College and Binghamton University. Explaining the gift in his will, Eckler wrote "Having spent most of my adult life in the United States, I wish, by certain gifts to my community, to express in a tangible way my appreciation for the opportunities that have been afforded me in this country and to do what I can by the trust ... to foster its noble ideals in the minds and hearts of future young Americans."

Dr. Eckler died in Binghamton on March 9, 1984.

See "Austrian dominated Ansco" (Binghamton Evening Press, March 11, 1984) and "Eckler's grand gift," Binghamton Press & Sun Bulletin, August 9, 1986).