The Monroe and Friday Night Dinner actress told Digital Spy that it was a matter of time before a female star is cast in the title role of Doctor Who.
Asked what she thought of Matt Smith compared to 'her Doctor David Tennant', Oberman said: "He's brilliant! My Doctor really was Tom Baker, but they're all my Doctors.
"I think next time there'll have to be a female Doctor. There has to be at some point."
She added: "I could see Sandi Toksvig as the Doctor... she'd be very Doctor-like! But it'll probably be Cheryl Cole, won't it?"
Of whether she could ever return to the show after playing Yvonne Hartman in series two finale 'Army of Ghosts' and 'Doomsday', she added: "I love Doctor Who.
"Even if I was just to come back and smile in the back of shot I'd be very happy to do it."
Showrunner Steven Moffat has has refused to rule out the possibility of a female Doctor.
"A Time Lord could potentially turn into a woman," he said at this year's Edinburgh International Television Festival.
"The more often it's talked about, the more likely it is to happen someday, I suppose."
However, Smith has suggested that a female Doctor is unlikely "any time soon" despite naming the "kick-ass" Charlize Theron as a possible candidate.
"There are many actresses that could play it because there are so many wonderful actresses," he said.
"Would it change the fundamentals of the character? No. But it's an interesting idea."
