Miranda was reunited with Gary after a cliffhanger ending to the second-last episode, where he stormed out after Miranda doubted his commitment to her.
Series creator and star Miranda Hart tweeted before the screening: “Goodbye to my creative baby day. Can’t promise but you MIGHT get a glimpse of that @GaryBarlow”.
Fans reacted positively to the episode, with many saying they had been reduced to tears by the emotional ending of the series.
Tom Ellis tweeted: “Wow. What an amazing response to the final #Miranda. Thank you to everyone who has watched over the past 5 years. It has been truly special.”
The show was launched in 2009 and has run for three series. It has won critical acclaim for its slapstick comedy, likeable central character and old-fashioned humour.
The first episode of the third series was the most-watched television programme at Christmas in 2012.