The first item of clothing with a company logo was a?
A vexillologist is a person who studies?
Answer: Bathing suit
Clothing covered with large and small logos is common today, but such branding was still unknown in the early 20th century. In fact, the first logo to appear on manufactured garments did not appear until 1923, when the swimwear company Jantzen began to label their swimsuits with a tiny little diver's logo, which can be seen here.
The “diving girl”, as she became known, was prominently represented both as a logo on clothing and in early advertising. The logo remains one of the world's longest-lasting apparel icons, as it has been used with very minor changes since its publication in print advertising in 1920.