Ralph Waite (June 22, 1928 - February 13, 2014) was an American actor, whose most notable role was playing John Walton Sr. on the 1970s CBS TV series The Waltons, which he also occasionally directed. He was also known for his portrayal of the slave ship third mate Slater, in the mini-series Roots.
In addition, he has appeared in many guest roles on numerous television series portraying a large variety of roles. He also played Jackson Gibbs, the father of main character, Leroy Jethro Gibbs (Mark Harmon) on NCIS.
Waite passed away on February 13, 2014 at the age of 85 from an unnamed age-related illness and as such, the NCIS Season 11 finale episode, Honor Thy Father (episode) was dedicated to him.