Darrow was Patron of the University of York Astronomy Society (AstroSoc) 1981-1984.

Proud of his work on Blake's 7, Darrow has acted as the show's most prolific spokesman, both in the UK and during the late 80s, in the U.S., when the show was frequently broadcast on US public television. In the mid to late 1990s, he purchased the rights to Blake's 7 and attempted to produce a big-budget follow-up mini-series, Blake's 7: A Rebellion Reborn. According to Darrow, it would have begun 25 years after the ending of the original series and might have included an aged Avon passing the torch to a new generation.

Darrow played the role of Samuel Vimes in the 1998/9 touring production of the play based on Terry Pratchett's Discworld novel "Guards! Guards!".

In 2004 Darrow was the subject of the fourth volume of MJTV's "The Actor Speaks" audio CDs, featuring frank interviews and dramatic pieces, alongside guest Peter Miles, with a piece specifically written by Tanith Lee.

Darrow records voiceovers and straplines for UK Jack FM station in Oxfordshire. He also provides the voice of the character Grand Moff Tarkin in the computer game Star Wars: Empire at War. He also voiced the character of Zarok in the PlayStation game MediEvil. Darrow appeared in Emmerdale from 13 July 2009, playing Eddy Fox, a friend of Alan Turner's; he knows Turner as "Tank".

In December 2011 Darrow voiced the character of Overseer Tremel in the Bioware MMORPG release Star Wars: The Old Republic.

In 2012, Darrow returned to the role of Kerr Avon in Big Finish Productions' Blake's 7: The Liberator Chronicles, a series of dramatic readings which take place during Series One before the death of Olag Gan. Darrow stars as Avon in The Turing Test and The Magnificent Four.

Darrow's other TV appearances include: Emergency – Ward 10, The Saint, Z-Cars, Dixon of Dock Green, Within These Walls, as the Sheriff of Nottingham in the 1975 BBC series The Legend of Robin Hood, as Mr. Tallboy in the 1973 TV adaptation of Dorothy L. Sayers' Murder Must Advertise, as Thomas Doughty in the TV film Drake's Venture, Dombey and Son, Maelstrom, Making News, Pie in the Sky, Hollyoaks, Toast of London and Little Britain. He provided the voiceover for Biblical quotations in Richard Dawkins's The Root of All Evil?. He was also the presenter of the 2004 BBC3 reality TV series Hercules. His film credits are few but include roles as doctors in The Raging Moon (1971) and the Bond movie Die Another Day (2002).

In 2015, Darrow starred as Paul Rand, the enigmatic Business man in charge of the Business institute Atlas in the interactive video game "Contradiction: Spot the Liar!". A sequel is planned in 2016.

In 2016, Darrow released an audio book of himself reading his autobiography "You're Him, Aren't You?".