Stetson

A Stetson was a type of wide-brimmed, high-crowned hat. It was typically associated with the western United States. Not only did the Eighth Doctor receive one from the eminent American Samuel Clemens, (COMIC: Bad Blood) but Craig Owens instantly gave the Eleventh Doctor a Stetson when he heard the Doctor was bound for America. (TV: Closing Time)

The First Doctor periodically wore a Stetson while he was preventing the Daleks' Master Plan. (TV: The Daleks' Master Plan)

When in Nevada in 1861, the Eleventh Doctor wore a Stetson as an alternative to a fez. (PROSE: The Good, the Bad and the Alien)

After the TARDIS materialised in Buzzard Creek, Arizona in 1905, the Fifth Doctor gave his companion Turlough a Stetson. Turlough regarded Stetsons as silly and commented that they were only worn by actors in "those ridiculous cowboy films." However, he was soon grateful that the hat offered him shade from the sun. (AUDIO: Freakshow) The Eleventh Doctor was given one by Craig Owens, from his friend Sean's stag. (TV: Closing Time) He wore it to Calisto B, Vegas 12 and the Seventh Transept before having the Teselecta impersonate him. The real version of the Doctor wore the Stetson while he was inside the Teselecta. The Teselecta created its own Stetson to impersonate the Doctor's. (TV: The Wedding of River Song)

In Utah, the disguised Teselecta (with the Doctor on board controlling it) met up with Amy and Rory. When Rory complimented him on the hat, he replied, "I wear a Stetson now. Stetsons are cool," before the Teselecta's Stetson was shot off its head by River Song. (TV: The Impossible Astronaut). The Doctor had the real Stetson on when the Teselecta faked the Doctor's death at Lake Silencio.

The Doctor later wore another Stetson while protecting Mercy from Kahler-Tek in 1870. Once he made Tek the new Marshal, he gave the Stetson to Tek. (TV: A Town Called Mercy)

In his eighth life, the Doctor visited the Lakota Sioux Nation and met General George Armstrong Custer. During this encounter, he was wearing a Stetson given to him by Samuel Clemens. (COMIC: Bad Blood)

The Eleventh Doctor sometimes wore a Stetson to perform his duties as a sheriff on Trenzalore. (PROSE: The Dreaming)

Jeffries of Proxima 2 wore a Stetson. (PROSE: The Face-Eater)

Behind the scenes
The model of Stetson hat worn by the Eleventh Doctor is called the "Hutchins."

Stetson hats are manufactured in Missouri and Texas.