Who is Ruby Sunday? The new Doctor Who companion explained

The Doctor Who Christmas special, ‘The Church on Ruby Road’, introduced Millie Gibson’s Ruby Sunday — here’s everything you need to know about the Doctor’s new companion.

It’s worth noting Ruby wasn’t the only fresh face in the Christmas special. The festive-themed adventure also marked the Fifteenth Doctor’s proper debut, following his introduction in the final Doctor Who 60th anniversary special, ‘The Giggle’.

The Doctor without a companion is hardly a Time Lord at all, and Ruby Sunday will be his time-travelling partner throughout this new era. As a young woman with a mysterious past, Ruby is set to bring chaos and drama to Doctor Who Season 14, but before you watch Doctor Who‘s new phase, you should get acquainted with Miss Sunday.

Here’s everything you need to know about Ruby, where she comes from, and how long she’ll be in the show for.

Who is Ruby Sunday in Doctor Who?

Ruby Sunday is the Fifteenth Doctor’s new companion, played by Millie Gibson, who was introduced in the Doctor Who 2023 Christmas special and was abandoned by her mother as a baby.

Ruby’s infant abandonment brings some mystery to the show, especially since the question mark around the identity of her mother is likely to form part of Season 14’s arc. What we do know about Ruby’s past is that she was left on a church doorstep as a baby on Christmas Eve. The Doctor Who Christmas special further establishes that Ruby’s name is derived from the church itself, which was situated on Ruby Road.

‘The Church on Ruby Road’ also revealed that Ruby was adopted by her foster mother, Carla (Michelle Greenidge). When the special kicks off, 19-year-old Ruby and Carla are living in Notting Hill, along with Ruby’s grandmother, Cherry (Angela Wynter).

The identity of Ruby’s birth mother is still up in the air. Some fans theorize that she could be Jodie Whittaker’s Thirteenth Doctor — and both women do seem to favor the same footwear. There’s not enough evidence in the special to confirm this theory, though.

In a recent interview with SFX, showrunner Russell T Davies hinted this puzzle will play out over Doctor Who Season 14.

“Not every question is answered in the Christmas special,” Davies teased. “And that continues all the way through to the most magnificent finale ever shot on planet Earth. No hype! I swear that’s true.”

How does Ruby Sunday meet the Doctor?

Ruby Sunday first encounters the Fifteenth Doctor in a London nightclub where they share a brief exchange, during which the Doctor hints that Ruby’s recent bad luck is more than it seems.

The pair stay strangers at this point (although the Doctor does wish Ruby a “Merry Christmas”). The Doctor and Ruby’s formal introduction comes later in the special, while they’re chasing after baby-snatching goblins.

Dangling precariously from the goblins’ airship, the Doctor and his soon-to-be companion finally swap names and quickly form an effective partnership. Indeed, it’s hardly surprising that when the special ends, Ruby joins the Fifteenth Doctor on his next adventure.

How long will Ruby Sunday be the Doctor’s companion?

Ruby Sunday will only be the Doctor’s companion during Doctor Who Season 14, as Millie Gibson is leaving after just one season and being replaced by Varada Sethu.

Once the current season ends, Varada Sethu (who fans will recognize from Andor Season 1), will star as the Doctor’s new companion. No information about the Season 15 companion has been confirmed yet, though it does suggest that a big ending could be in the works for Ruby during the Season 14 finale.

But Gibson will see out the rest of Season 14 as the Doctor’s right-hand woman, so essentially, Ruby Sunday will appear in at least eight Doctor Who episodes.

Doctor Who: The Church on Ruby Road is now streaming on BBC iPlayer (UK & Ireland) and Disney+ (everywhere else). For more, check out the full Doctor Who Season 14 release schedule, and check out our thoughts on the first two episodes with our ‘Space Babies’ review and ‘The Devil’s Chord’ review.