A crossover between Sherlock Holmes and Doctor Who was once viewed as a real possibility, particularly with Steven Moffat playing a key creative role on both BBC series. Despite years of fan speculation and internal discussions, the project never moved forward. Moffat has now revealed that the decision ultimately came down to creative concerns.
Why Benedict Cumberbatch’s Sherlock and Matt Smith’s Doctor Who never got a crossover
Although Doctor Who and Sherlock were two of the BBC’s most successful series and both were shaped by Steven Moffat, a crossover between Matt Smith’s Eleventh Doctor and Benedict Cumberbatch’s Sherlock Holmes never happened. Moffat said the two shows were too different to share the same world without changing the nature of Sherlock.
Discussing the idea during an appearance on The Whoniverse Show, Moffat revealed that the proposal was considered far more seriously than many viewers knew. According to the writer, fan interest was so strong that he and Sherlock co-creator Mark Gatiss even explored producing a crossover as part of Comic Relief. “It came up every second. Everybody wanted us to do it,” Moffat recalled, adding that the special came “very close to happening.”
Despite that enthusiasm, the creative team ultimately concluded that the crossover would create major problems for Sherlock. Moffat explained, “Then how does Sherlock cope with the fact that time travel he now knows exists? Doesn’t that change every case he then tries to solve? I don’t think the two worlds are compatible.”
He also believed the Doctor and Sherlock would spend much of their time competing with one another because of their brilliant minds and strong personalities. Moffat said, “And they’d probably just have a big dust-up in the TARDIS. Both sulk and refuse to come out because there was somebody else in the room who was maybe smarter than them.”
Furthermore, the writer added that he would still enjoy seeing the two characters compete in a quiz to determine who “came out on top.”
