Doctor Who is one of the most popular sci-fi shows of all time and is constantly evolving. Some things have stayed the same over the years, but one thing that always changes is the Doctor's companions. The Time Lord can carry on whizzing through time and space for thousands of years, but his friends can't stay with him forever.

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Saying goodbye to these companions can be a tough process for fans, particularly given some of the heartbreaking ways that these beloved characters have left the show. Whether it's bittersweet farewells or tragic fates, Doctor Who has never shied away from leaving fans with a tear or two in their eyes when it comes time for a companion to step out of the TARDIS for the final time.

10 Ian and Barbara: “It Was Fun Doctor, Goodbye”

Doctor Who Ian and Barbara

Ian and Barbara were with the Doctor at the start of the series and became his first human companions, but they didn't travel willingly. Ian and Barbara were taken by the Doctor and ended up spending two years traveling in the TARDIS with him as he aimed to get them back to 1960s Earth.

Ian and Barbara are finally given the opportunity to return to the 1960s, but the Doctor refuses to help them go back because he doesn't want them to leave. Companion Vicki eventually persuades him and the Doctor caps off the episode with a simple but profound, "I shall miss them."

9 Bill: "I Hope I See You Again"

Doctor Who Bill becomes a cyberman

Bill traveled with the Twelfth Doctor, and they shared a student/professor relationship reminiscent of the Seventh Doctor's and Ace's in the Classic series. Bill only stuck around for one series, but she stood out thanks to her curious and energetic nature that kept the Doctor on his toes.

One of the worst fates to suffer in the Doctor Who universe is being converted into a cyberman which is what makes Bill's departure all the more harrowing. Fortunately, Bill is saved by the pilot, but both she and the Doctor part ways unaware that the other survived.

8 Tegan: "It's Stopped Being Fun, Doctor"

Doctor Who Tegan Leaves

Tegan was an Australian air stewardess from Earth who accompanied the Fourth Doctor briefly before he regenerated and the Fifth Doctor for most of his era. Tegan experienced her fair share of trauma while aboard the TARDIS, so her sudden exit felt like a natural progression for her character.

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Tegan's exit is arguably one of the most realistic for a companion as she decides that enough is enough. After witnessing the bloodbath that takes place in "Revelation of the Daleks," Tegan tells the Doctor that she's sick of everyone dying and that "it's stopped being fun." Tegan then runs off with the Doctor calling after her adding to an already dark and somber story.

7 Susan: "One Day I Shall Come Back"

Doctor Who Susan Leaves

Susan was the Doctor's granddaughter and the first companion to leave the TARDIS, so it was always going to be an emotional farewell. Her exit is probably one of the most recognizable in the Classic series and that's thanks to Hartnell's farewell speech which has become immortalized amongst fans.

The Doctor leaves Susan behind on 22nd century Earth after she falls in love with David: one of the human resistance fighters who helped the TARDIS team beat the Daleks. What follows is a moving speech from the Doctor in which he explains to Susan how he wants her to have a life where she can belong instead of wandering through time and space.

6 Jamie And Zoe: "I Won't Forget You"

Dr Who Jamie and Zoe Leave The Second Doctor

Jamie and Zoe were companions to the Second Doctor and Jamie holds the record for being the longest-serving companion in the show with him appearing in 113 episodes. Jamie and the Second Doctor were inseparable and had a dynamic that has been rivaled by few other TARDIS teams.

The Doctor is summoned by the Time Lords and forced to regenerate as a result of his "interfering" with time. Before this happens though, Jamie and Zoe are taken back to their own times and Jamie utters the line "I won't forget you." However, upon being returned, the Time Lords explain how both Jamie and Zoe's memories will be wiped, so they can only retain the memory of their first adventure with the Doctor.

5 Amy And Rory: "Don't Be Alone"

Doctor Who Amy and Rory Leave

Amy and Rory traveled with the Eleventh Doctor for most of his tenure and the three became like a family. Amy and Rory's relationship was continuously tested during their time in the TARDIS, but their final outing showed fans just how strong their love was in the end.

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After Rory is touched by a weeping angel and sent back in time, Amy doesn't hesitate to let the angel touch her too so that the pair can remain together. While the ending isn't entirely sad due to Amy and Rory getting to live out their lives together, it's the Doctor's reaction that shines through here as Smith flawlessly displays the Doctor's grief and emotional turmoil at losing his two best friends.

4 Sarah Jane: "Until We Meet Again, Sarah"

Sarah-Jane-says-goodbye-dr-who

Sarah Jane Smith is the most iconic companion in Doctor Who and so it's no surprise that her exit is a sad one. The Doctor is called back to Gallifrey, which, at the time, did not allow humans, so he has no choice but to leave Sarah on Earth. It's clear that neither of them wants to part ways, and Sarah leaves with the touching line "Don't forget me."

Sarah's ending only gets sadder, however, when she reunites with the Doctor in "School Reunion" and explains how she thought he would return for her. Fortunately, Sarah sees the Doctor again several times after this, and, as a result, she holds the record for the companion who has met the most incarnations of the Doctor on-screen, including the First, Second, Third, Fourth, Fifth, Tenth, and Eleventh.

3 Jo: "Don't Go Too Far Away"

Doctor-Who-Jo-Grant-Departure

Jo Grant was the Third Doctor's companion for three seasons and is a fan-favorite thanks to the excellent chemistry between Katy Manning and Jon Pertwee. Jo eventually decides to leave the Doctor after getting engaged to Clifford Jones, which leads to one of the most tender and poignant moments in all Classic Doctor Who where the Doctor promises that he'll see her again and drives away in his car alone.

However, as the Doctor often does, he fails to stick to his promise, and is once again faced with the repercussions of abandoning his companions in the Sarah Jane Adventures episode, "Death of the Doctor." In the episode, Jo meets the Eleventh Doctor, and he reveals to her that he doesn't go back because he "can't" but that the last time he was dying he looked back on "every single one" and "was so proud."

2 Rose: "How Long Have We Got"

Doctor Who Rose Exit

Fans have been shedding tears over Rose's departure since it first aired on television way back in 2006. Rose remains one of the most popular companions in the show, and her relationship with the Doctor was akin to a romance in everything but name.

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Rose became trapped in a parallel universe unable to see the Doctor again, but before the universes sealed themselves off, the Doctor was able to project an image of himself to say goodbye. The scene that follows is heart-wrenching as Rose confesses her love and the Doctor is cut off mid-sentence leaving his final words to her unknown.

1 Donna: "Don't Make Me Go Back"

Doctor Who Donna Leaves

Donna traveled with the Tenth Doctor and is easily one of the most popular companions in the show's history, but she suffers from the most tragic departure. After a human/Time Lord metacrisis starts to burn up her mind, the Doctor is forced to wipe it completely so that all traces of him and their adventures together are gone.

When fans are first introduced to Donna she’s an outspoken and closed-minded woman who's unhappy with the state of her life. But, as she travels with the Doctor, she grows to become compassionate and intuitive and starts to realize her self-worth. This only makes her exit all the more cruel, as her entire arc is reversed and that version of her is essentially killed.

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