A t-shirt was an item of clothing.

The older Norman Bean wore a Buffy the Vampire Slayer T-shirt. (PROSE: Homework)

When Joel Mintz met the Seventh Doctor and Chris Cwej in 16th century Japan, he was wearing a Real Ghostbusters t-shirt. (PROSE: The Room With No Doors)

Kamala sold t-shirts in his shop in Borneo that said "I SAW THE UNTHINKABLE CITY AND LIVED!" (PROSE: Alien Bodies)

Rose Tyler wore t-shirts done on grey, (TV: Rose) pink, (TV: Aliens of London/World War Three) Union flag, (TV: The Empty Child/The Doctor Dances) a blue Wichita Falls t-shirt, (TV: The Girl in the Fireplace) amber, (TV: Fear Her) black (TV: Army of Ghosts/Doomsday) and rose. (TV: Partners in Crime, Turn Left, The Stolen Earth/Journey's End)

Martha Jones wore a dark teal t-shirt with her white lab coat. (TV: Smith and Jones) or her maroon leather jacket. (TV: The Infinite Quest)

The Eighth Doctor wore an alabaster t-shirt with his navy leather peacoat. (AUDIO: Fugitives, onwards)

Under her lilac blue trench coat, the Thirteenth Doctor wore a variety of similarly designed t-shirts with rainbow stripes running across their chest, such as a low collar navy blue shirt, (TV: The Woman Who Fell to Earth) a dark pink low collar shirt, (TV: Rosa) a dark pink crew collar shirt, (TV: The Tsuranga Conundrum) a navy blue crew collar t-shirt with a smeared rainbow pattern, (TV: Kerblam!) light blue crew collar shirt, (TV: Resolution) and a dark purple crew collar shirt. (TV: Revolution of the Daleks)

Ace wore t-shirts done in white, (TV: Remembrance of the Daleks, Silver Nemesis) emerald (TV: Battlefield) or crimson. (TV: Survival)

Whilst on the SS Madame de Pompadour, Mickey Smith wore a t-shirt with a picture of the Nintendo Entertainment System controller over the caption, "Know Your Roots". (TV: The Girl in the Fireplace)

After avoiding his own death at Lake Silencio, River Song bought the Eleventh Doctor a t-shirt saying "I died at Lake Silencio and all my wife got me was this lousy t-shirt". (PROSE: Houdini and The Space Cuckoos)

Grace O'Brien owned a t-shirt that said "The Spirit of Rosa". (TV: Rosa)

Trine owned an Arctic Monkeys t-shirt. After her death, it was worn by her daughter Hanne. (TV: It Takes You Away)