He portrayed PC "Fancy" Smith in Z-Cars; Augustus in the 1976 BBC television production of I, Claudius; King Richard IV in the first series of Blackadder; Prince Vultan in Flash Gordon; Bustopher Jones and Old Deuteronomy in the 1981 original London production of Cats at the New London Theatre; Thomas Beaufort, Duke of Exeter, in Henry V; Boss Nass in Star Wars: Episode I – The Phantom Menace; and the voice of Clayton and the Tarzan yell in Disney's Tarzan.

He played Caesar Augustus in the BBC Two drama series I, Claudius (1976),[14] Vargas in the Blake's 7 episode Cygnus Alpha (1978) and Basileos in The Aphrodite Inheritance (1979).

Blessed played Long John Silver in the 10-part serial Return to Treasure Island (1986), King Yrcanos in the Doctor Who serial Mindwarp (1986), General Yevlenko in the mini-series War and Remembrance (1988), and Lord Loxley, the father of Robin Hood, in the Hollywood film Robin Hood: Prince of Thieves (1991).

In 1981, Blessed appeared in Andrew Lloyd Webber's musical, Cats, as both Old Deuteronomy and Bustopher Jones, for the original West End theatre production.

In comedies, Blessed portrayed Prince Vultan in the film Flash Gordon (1980);[17] the mad, comical figure of Richard IV in the first series of The Black Adder (1983), a role Blessed has claimed to be one of his most cherished[citation needed]; and Spiro Halikiopoulos in the TV mini-series My Family and Other Animals (1987), a BBC adaptation of Gerald Durrell's book by the same name.

He later recalled accidentally punching Peter Capaldi whilst filming and said of the event, "I thought I'd killed the poor bastard.

"[21] In 1999, Blessed provided both the voice and live-action reference for the CGI character Boss Nass in Star Wars: Episode I – The Phantom Menace, and also provided the voice of the villainous hunter Clayton in Disney's animated feature film Tarzan, a role he later reprised in the video game based on the film and in the critically acclaimed Kingdom Hearts in 2002; he also did the Tarzan yell after Tony Goldwyn was unable to do it himself.

He has further provided vocal links for the Sony-Award-winning Christian O'Connell Breakfast Show on Virgin Radio, and introduced advertisements for Orange mobile phones.

From December 2005 to January 2006, Blessed headlined the Christmas pantomime production of Peter Pan, alongside CBBC presenter Kirsten O'Brien, at Ipswich's Regent Theatre.

[citation needed] From 2007 to 2008, he appeared in the same play as Captain Hook at the Grove Theatre in Dunstable; he reprised the role for the Christmas 2008 season at the Fairfield Halls, Croydon.

[25] In September 2010, Blessed recorded the voice of Great Sultan Shahryār for Sheherazade, or The Princess, the Pirate and the Baboon!, an album of children's stories set to Nikolai Rimsky-Korsakov's classical music composition Scheherazade, co-starring Rory Bremner and released as an instalment of Grandma Dingley's Ingeniously Musical Tales in 2011.

[26] In 2018, Blessed voiced German military engineer Konrad Kyeser in the open-world medieval RPG, Kingdom Come: Deliverance.

[30] Blessed has reached the summits of Aconcagua in Argentina and Kilimanjaro in Tanzania,[31] and has undertaken an expedition into the jungles of Venezuela, during which he survived a plane crash.

[32] Blessed is the oldest man to have reached the North Magnetic Pole on foot,[33] where he says he punched a polar bear on the nose.

[34] In 2009, Blessed featured in the song "Army of the Damned" from the album Beneath the Veiled Embrace by British power metal band Pythia, reciting the poem "Suicide in the Trenches" by Siegfried Sassoon.

[40] In 2004, Blessed appeared on and won an episode of Celebrity Stars in Their Eyes, impersonating the opera singer Luciano Pavarotti.

[53][54] On 19 January 2015, Blessed collapsed on stage during a performance of King Lear with the Guildford Shakespeare Company, in which his daughter Rosalind was also acting.