Which Doctor was portrayed by Peter Capaldi?

Peter Capaldi portrayed the Twelfth Doctor in Doctor Who. He took over the role after Matt Smith’s Eleventh Doctor and made his first full appearance in the 2013 Christmas special “The Time of the Doctor,” following the Doctor’s regeneration.

Capaldi’s Doctor was older, sharper, and more abrasive than his immediate predecessor. His era explored whether the Doctor was fundamentally a good man, particularly through his evolving friendship with Clara Oswald. The character travelled in the TARDIS, confronted threats such as the Master’s latest incarnation, and eventually faced the consequences of his long life.

Capaldi played the Doctor from 2013 to 2017, appearing across Series 8, 9, and 10. He was followed by Jodie Whittaker as the Thirteenth Doctor. The main mix-up in this question is with the Eleventh Doctor, played by Matt Smith, or the Ninth Doctor, played by Christopher Eccleston.