Played by Michael Mckean
Divorced from Tom and Bea's mother for many years, Keith is now remarried and retired from his job as a Yeoman Warder ("Don't call us Beefeaters!") at the Tower of London. He spends his time following his beloved Tottenham Hotspurs Football Club, watching dvds of 1970's sitcoms, and trying to come up with an invention that will help change the world. Keith definitely doesn't share Tom's interest in his family's history and thinks that genealogy "like every other ology, is best left to the scientists."