Tate made her first appearance alongside David Tennant's incarnation of the Doctor in the 2006 Christmas special The Runaway Bride and then returned as a full-time companion for the fourth series in 2008.
Donna was written out of the show in the 2010 special episode The End of Time, which culminated in her being forced to forget her adventures with the Doctor.
In a poll for Radio Times, Donna won 23 per cent of the vote for best companion — ahead of Captain Jack Harkness (John Barrowman), who earned 21 per cent.
Watch: Catherine Tate hinted at Doctor Who return, as interview resurfaces
Billie Piper came in third place for her work as Rose Tyler, with the top five made up by Clara Oswald (Jenna Coleman) and Donna's grandfather Wilf Mott — played by the late Bernard Cribbins.
Tate is due to return alongside Tennant for the show's 60th anniversary celebrations next year, which will also introduce Neil Patrick Harris as a villain.
Doctor Who will return to screens in October for a special episode to mark the BBC's centenary, which will feature the departure of Jodie Whittaker from the lead role.
Whittaker has played the Doctor since 2018 and will be replaced in the role by Sex Education star Ncuti Gatwa — though there is speculation that Whittaker won't actually regenerate into Gatwa at this time.
Gatwa's arrival will mark the return of Russell T Davies as Doctor Who showrunner, with the shepherd of the original 2005 reboot replacing current head honcho Chris Chibnall.
The new lead will be joined in the cast by transgender Heartstopper actor Yasmin Finney, who will play a character called Rose.
Rumours in recent weeks have seen former EastEnders actor and Strictly Come Dancing winner Rose Ayling-Ellis connected to the show in the wake of her exit from the BBC soap.
The star denied she is in the frame for the show, but told Sky News that a part on Doctor Who would be "a great job" if it were to come around.
Watch: Rose Ayling-Ellis denies rumours she's joining Doctor Who