Although the line-up of the "seven" changed considerably over the show's four seasons, the original characters envisioned by creator Terry Nation for the seven were: Kerr Avon, Vila Restal, Olag Gan, Jenna Stannis, Brell Klein, Tone Selman and Arco Trent (with Blake as their leader). They would all have joined Blake on the "Liberator" after their escape from the penal colony on Cygnus Alpha. However, subsequent rewrites, and budgetary restrictions, saw the characters of Klein, Selman and Arco being dropped (although Selman and Arco made short-lived appearences in the 3rd episode, "Cygnus Alpha") and replaced with Cally, Zen and later Orac (both computers, voiced by the same actor to reduce expenses).

Michael Keating (Vila Restal) is the only actor to appear in all 52 episodes of the series. In second place is Paul Darrow (Kerr Avon) who appeared in every episode except the first. In third place is Peter Tuddenham who variously voiced Zen, Orac, Slave and various other computers in forty-nine episodes, missing out the first two and also the second season episode Countdown.

That endless corridor that the team were always dashing around the ship in was only about 20 feet long with a short tee on one end.

Gareth Thomas and Tom Baker always wanted to do a cross-over between Doctor Who and Blake's 7 but this was vetoed by producers of both series. Indeed the invasion from Andromeda at the end of the second season was originally going to be invasion by Doctor Who's Daleks, also created by Terry Nation.

Blakes 7 is currently being digitally re-mastered and will be released on DVD at various times in 2004-2005. DVD extras include a documentary on how they made the series as well as other extras soon to be confirmed.

Marina Sirtis auditioned for the part of Dayna.

Production standards are generally low. Sets wobble and props malfunction. Continuity errors abound.

The final episode ends with a lone Avon, surrounded by Federation soldiers, holding a blaster-type rifle and smiling a devious smile. The program then cuts to the end titles visually, but several "shots" are heard over the credits before the theme music starts.

There were two radio plays commissioned in the late 1990's, set during the fourth season they featured most of the original cast returning to their TV roles.  However both Soolin and Dayna were recast as the original actresses were either unable or unwilling to return to the series.  To replace the original stars of the series, Angela Bruce was cast as Dayna and Paula Wilcox was cast as Soolin.

According to actress Jacqueline Pearce, who played Servalan, Terry Nation originally intended her character to be a man, but halfway through writing the script he realised that it would be more interesting if the gender was reversed. Servalan was also meant to make only one appearance, but Pearce's commanding performance, great beauty and unusual close-cropped hairstyle made Servalan an instant hit and Pearce became a regular cast member.