There have already been 13 doctors, from William Hartnell to Jodie Whittaker so who could be next in line as the new Doctor Who? Whittaker is rumoured to be leaving the show after the 13th series, which is set to air later in 2021. In her final outing as Doctor Who, she will lead alongside her new assistant, comedian John Bishop. While there has been no confirmation of who will lead after Whittaker’s departure from the Tardis, there has been plenty of speculation. Here, we take a look at the bookies’ favourites for the next Time Lord. Kris Marshall Odds 4-1 My Family and Love Actually star Marshall has been the dark horse since it was revealed there would be a new doctor. However, in recent days he has shot into the lead in the odds and this is not the first time it has been rumoured he is the next Time Lord. Marshall is currently starring in the BBC’s Death in Paradise, but he has confirmed this is his last series after four years on the show/ Speculation is now circling that this is because he is returning to the UK to shoot the 14th Doctor Who series. Coral’s press manager, John Hill said: “Kris Marshall has recently been shining on Death In Paradise but this series could be his last in Saint Marie as he is the favourite to replace Jodie Whittaker as the next Doctor Who.” Michaela Coel Odds 6-1 The I May Destroy You actress has been considered the favourite to replace Whittaker since rumours began at the beginning of the year that a new doctor would be cast. Despite Marshall taking the lead now, Coel is still considered a favourite and would be only the second female doctor. The actress was recently denied a Golden Globe nomination, much to the shock and dismay of screenwriters and TV critics. Richard Ayoade Odds 8-1 Crystal Maze host and IT crowd star Ayoade emerged as the second most popular replacement for Whittaker, back in January, but has now fallen to third place. His dry sense of comedy and geeky style would make him the perfect candidate, but odds have gone against him in recent weeks. Ayoade also recently voiced Zero in The Mandalorian, so his sci-fi charm is strong, and having already won a BAFTA for Best Male Comedy Performance, his acting is out of this world too. Phoebe Waller-Bridge Odds 8-1 The BBC’s Fleabag screenwriter and leading actress has found herself in the running to be the next doctor, again. She was the favourite to replace the Time Lord back in 2017, before being snubbed for Whittaker - Whittaker later said she wanted to apologise to the actress for this. Whittaker told Dermot O’Leary on BBC Radio 2, upon announcing she was the next doctor: “At no point could I just text her and go, ‘I’m so sorry’ – because I was under the radar the entire time until the last few days.” Back in 2017, Waller-Bridge said of the opportunity to become the next doctor: “Um, it’d be cool, but I might be doing other stuff." Olly Alexander Odds 8-1 He may be the least predictable suggestion we have seen thrown into the mix, but John Barrowman has said he would love to see Alexander as the next Time Lord.. The Years and Years singer has recently shot into the acting limelight with his emotive and stunning performance in Channel 4’s It’s a Sin. Russell T Davies, who used to write and produce Doctor Who, is also the writer of It’s a Sin. Barrowman told Lorraine: "Olly would be amazing – he's quirky, he's fun, he's a lovely actor and I think he would make a wonderful Doctor." When is Doctor Who back on TV? The 13th series of Doctor Who has been confirmed to air later in 2021, confirmed the BBC. It will be available to watch on BBC1 and BBC iPlayer. You can currently watch all 168 previous episodes, from series 1-12, on BBC iPlayer. Whichever actor is confirmed as the next doctor will feature in the 14th series, onwards.