No they are not related.
Actors Robert & Philip Glenister however are related. Their father is director John Glenister.
The cast of Cryptic - 2014 includes: Philip Barantini as John Jonas Vas Blackwood as Meat Daniel Feuerriegel as Jim Jonas Robert Glenister as Robert Sally Leonard as Alberta Ray Panthaki as Cochise Ben Shafik as Walter Ed Stoppard as Steve Stevens
The cast of Victoria Station - 2003 includes: Robert Glenister as The controller Rufus Sewell as The cabbie
The cast of Behind the Scenes of... Episode 3 - 2007 includes: Peter Brayham as himself Philip Glenister as himself Marshall Lancaster as himself Cameron Roach as himself Julie Rutterford as herself Gabriel Silver as himself John Simm as himself Darren Wallis as himself Luc Webster as himself Alan Whibley as himself
The cast of Roosevelt and Truman - 1977 includes: Art Evans as Roosevelt Richard Karron as Richie Philip Michael Thomas as Truman Ilka Tanya Payan as Juanita
The cast of From the Badlands to Alcatraz - 2009 includes: Arlene Iron Cloud as Arlene Iron Cloud Arlo Iron Cloud as Arlo Iron Cloud Philip Iron Cloud as Philip Iron Cloud Richard Iron Cloud as Richard Iron Cloud Kelly Waters as Kelly Waters Lisa Waters as Lisa Waters Alkapoane White Calf as Alkapoane White Calf
The cast of The Secret Life of the National Grid - 2010 includes: Philip Glenister as Himself - Narrator
No.
No, they are not related. Jonathan Harris had a son named Richard, but he is a different person (born 1942). The actor, Richard Harris was born in 1930. Coincidently, both actors Jonathan and Richard died 2002 a little less than a month apart.
The cast of Secret Honor - 1984 includes: Philip Baker Hall as Richard Nixon
The cast of Untitled Richard LaGravenese Project - 2014 includes: Katie Holmes as Ann Rufus Sewell as Philip Fitzgerald Julien
The cast of Distress Signals - 1998 includes: Richard Lumsden as Philip Wednesday Hoyt Richards as Troy Stewart
The cast of The Perfect Blue - 1997 includes: Michele Austin as Frances Inday Ba as Sunny Yvonne Brewster as Mrs Jordan Katie Carr as Katie Ruth Gemmell as Jo Philip Glenister as Tom Lennie James as Danny Michael Liebmann as Ian
The cast of Cryptic - 2014 includes: Philip Barantini as John Jonas Vas Blackwood as Meat Daniel Feuerriegel as Jim Jonas Robert Glenister as Robert Sally Leonard as Alberta Ray Panthaki as Cochise Ben Shafik as Walter Ed Stoppard as Steve Stevens
The cast of Get Off My Land - 2007 includes: Robert Glenister as Farmer Rafe Spall as Man
The cast of Victoria Station - 2003 includes: Robert Glenister as The controller Rufus Sewell as The cabbie
The cast of Philips and the Monkey Pen - 2013 includes: Jayasurya as Roy Philip Mukesh Babu as Charles Leon Vijay Babu as Pappan Sir Joy Mathew as Richard Philip Ramya Nambeeshan as Sameera Roy Sanoop Santhosh as Ryan Philip
The cast of Philip Holden - Waster - 1916 includes: Richard Bennett as Philip Holden Clarence Burton as Robert Landon Orral Humphrey as Paul Merwin Rhea Mitchell as Helen Landon Adrienne Morrison as Louise Holden George Periolat as Miles Holden