!!The play
* BeamMeUpScotty: "Off with his head! So much for Buckingham." For many years one of Richard's most iconic lines -- but not part of Shakespeare's play. It was added in 1700 by leading-man Creator/ColleyCibber.

!!1955 film
* DawsonCasting: Although Creator/LaurenceOlivier was 47 when the film was made, the real King Richard III was only 32 when he died. King Edward IV was 40 when he died but was played by 61-year-old Cedric Hardwicke.
* DirectedByCastmember
* ProductionPosse: Creator/LaurenceOlivier reassembled the production team from his other Shakespeare films, including production designer Roger Furse, art director Carmen Dillon, composer William Walton and associate director Anthony Bushell. As with ''Henry V'', they modeled the film's look on the illustrations in the medieval Book of the Hours.
* RomanceOnTheSet: Creator/LaurenceOlivier was having an extra-marital affair with Claire Bloom during filming.
* ThrowItIn: In the opening of the film, Richard accidentally drops the Duke's coronet after the royal party leaves. It was a mistake that Creator/LaurenceOlivier made, but left in. However, it became a running joke throughout the film and later, you can see the same gag again.
* WhatCouldHaveBeen:
** Creator/LaurenceOlivier wanted to cast Creator/OrsonWelles in the role of Buckingham, but life-long friend Sir Ralph Richardson wanted the role, and Olivier gave it to him. In his autobiography, Olivier says he wishes he had disappointed Richardson and cast Welles instead as he would have brought an extra element to the screen, an intelligence that would have gone well with the plot element of conspiracy.
** Olivier originally wanted John Mills and Creator/RichardAttenborough to play the murderers. However, Mills thought the idea might be regarded as StuntCasting, and Attenborough had to pull out due to a scheduling conflict.
** Creator/VivienLeigh wanted to play Lady Anne, but Olivier chose the younger Claire Bloom instead. Alexander Korda then suggested he cast Leigh in a silent cameo, a role specially created for the film version, but instead Olivier convinced the producer to cast her in another of his films, ''The Deep Blue Sea'' (1955), a leading role he felt better suited to her talents.
** Olivier approached Creator/RichardBurton about playing Henry VII.
** Creator/RobertDonat was offered a role.

!!1995 film
* AwesomeDearBoy: Creator/IanMcKellen enjoyed acting with Creator/RobertDowneyJr in ''Restoration'' (1995), and asked him to play the part of Rivers, expecting him to turn the role down as too small. To [=McKellen=]'s surprise, Downey immediately cleared his diary, and took the part.
* DawsonCasting: Creator/IanMcKellen was in his fifties when he played King Richard III, who only lived to be thirty-three.
* WhatCouldHaveBeen: As a twelve-year-old, Creator/EddieRedmayne auditioned for a part as one of the princes in the tower, but was turned down by Sir Creator/IanMcKellen as being unsuitable.