He has too worked around Western theatre, acting within & directing Peter Brook's Marat/Sade on Broadway in 1965. He would play a section of Jean-Paul Marat again in the 1967 film version. He played Prof Harold Hill in the 1976 revival of The Music Man and received a Tony nomination. He besides appeared in Broadway in 1981 in the original production of Edward Albee's play Lolita, an adaptation of Vladimir Nabokov's book.

He has manufactured numbers of film appearances, a better known existence around Dark City (1998), but include such diverse roles when Polonius in Rosencrantz and Guildenstern Are Dead (1990) and Martin Landau's butler in the Halle Berry film B*A*P*S (1997).

Richardson's memorable TV performances when "Tailor" in the BBC adaptation of Tinker, Tailor, Soldier, Spy, and the Master of Porterhouse College in ITV's adaptation of Porterhouse Blue. He has besides starred around many installments of Execution Rooms (the BBC production also screened within PBS's Mystery! strand in the United States), playing Dr. Joseph Bell, the wise man of Arthur Conan Doyle. Around 2003 he played the revenant role of the nefarious Canon Black in the short-fugacious BBC fantasy series Strange.

He was processed the CBE in 1989.

In the early 2000s Richardson joined Sir Derek Jacobi, Sir Donald Sinden and Dame Diana Rigg in an international tour of The Hollow Crown.