He retired as an inspector for Tactair Fluid Controls, Inc. in Liverpool and he had previously worked at Sealright Co. in Fulton.
Leonard served in the U.S. Army during the 1960s.
He was the son of the late, Clyde and Madeline Daniels and was predeceased by a sister, Mary LaBoda.
Surviving are his wife of 55 years, Gladys Daniels of Fulton; two children, Julie (Christopher) Pepper of Volney and Alan (Susan) Daniels of Fulton; four grandchildren, Taylor and Cole Daniels and Zachary and Madison Pepper; siblings, Linda (Jim) Webb of Sackets Harbor and Robert (Jane) Daniels of Volney; many nieces and nephews.
The family will greet family and friends from 4 to 7 p.m. Monday, May 12 at Foster Funeral Home, 910 Fay St., Fulton.
In lieu of flowers, memorial gifts are encouraged to the Manor at Seneca Hill Activities Fund, 20 Manor Drive, Oswego, NY 13126 or to the VA Medical Center, 800 Irving Avenue, Syracuse, NY 13210.