Frock coat

A frock coat was a formal coat characterised by a knee-length skirt cut all around the base just above the knee, popular during the Victorian and Edwardian periods.

Worn by the Doctor
The First Doctor wore an Edwardian frock coat. (COMIC: Moon Landing, PROSE: Sanctuary)

The Fourth Doctor wore frock coats; one of burgundy velvet  (TV: Pyramids of Mars, The Masque of Mandragora - The Deadly Assassin) one of grey tweed (TV: The Android Invasion et al) one of chocolate brown velvet, (TV: The Face of Evil et al) and one of light brown Harris tweed. (TV: The Power of Kroll et al)

The Fifth Doctor wore a beige frock coat (TV; Castrovalva-Warriors of the Deep).

The Sixth Doctor initially wore a patchwork frock coat with several different colours and fabrics, (TV: The Twin Dilemma onwards) which he replaced with a similar coat in different shades of blue for a period (AUDIO: Real Time onwards) before returning to the original up to his death. (TV: Time and the Rani)

The Eighth Doctor wore many frock coats of velvet done in forest green, (TV: Doctor Who) navy blue, (COMIC: Dreadnought), olive green, (COMIC: Ophidius), or dark brown. (PROSE: The Year of Intelligent Tigers)

On the Titanic launching of 1912, the Ninth Doctor wore an ebony black moleskin frock coat. (TV: Rose)

During his retirement to the Victorian era, the Eleventh Doctor wore a burgundy frock coat. (TV: The Great Detective, The Snowmen) When travelling with Clara Oswald, he wore a frock coat of eggplant purple cashmere. (TV: The Bells of Saint John - The Time of the Doctor).

The Twelfth Doctor occasionally wore a black frock coat. (TV: The Pilot-Twice Upon A Time)

The Fugitive Doctor wore a navy tweed frock coat. (TV: Fugitive of the Judoon, The Timeless Children, Once, Upon Time)

The Curator, taking the form of an older Sixth Doctor, wore frock coats; one of violet moleskin, (AUDIO: Crossed Lines) and one of burgundy and peach pinstripe. (AUDIO: The Artist at the End of Time)

Worn by Companions
Romana wore frock coats on scarlet, (TV: The Horns of Nimon) or beige. (TV: State of Decay)

Won by the Master
Many versions of the Master wore frock coats.

The Saxon Master wore a black, asymmetrical frock coat when he met Missy, his gender-switched incarnation, along with the Twelfth Doctor. (TV: World Enough and Time|The Doctor Falls)

The Spy Master wore a plum purple tweed frock coat during his encounters with the Thirteenth Doctor. (TV: Spyfall, Ascension of the Cybermen|The Timeless Children)

Worn by others
Webley wore a double breasted frock coat of bottle green tweed with a scarlet overcheck. (TV: Nightmare in Silver)

Edward Waterfield and Theodore Maxtible wore frock coats; Edward's navy and Theodore's charcoal. (TV: The Evil of the Daleks)