Leinwohl was born and raised in Cincinatti, Ohio in 1940 and attended elementary and secondary school in the public school system. He came to Chicago and received his bachelor's degree in photography/graphic design in 1963. Upon graduating from the I.D. he worked with well-known studio photographers Morton Shapiro and Jack Desort and also did a good deal of film work. He then worked for a year as a photographer in the Public Relations Department of the Illinois Institute of Technology. In May of 1965 he opened his own studio handling creative advertising, corporate, industrial and magazine assignments. Leinwohl has been a guest lecturer for graduate seminars for photography and design at the Institute of Design, and the Art Institute of Chicago. He has won numerous national and international awards for his photography from design and art directors' clubs. Leinwohl's work has been featured in many international design and photography magazines and has contributed to many books. Leiwohl lives in Chicago.