A polo shirt, also known as a golf shirt and tennis shirt, is a T-shaped shirt with a collar, typically a two- or three-button placket, and an optional pocket. Polo shirts are usually made of knitted cloth (rather than woven cloth), usually piqué cotton or, less commonly, silk, merino wool, or synthetic fibers.

In the 19th and early 20th centuries, tennis players ordinarily wore "tennis whites" consisting of long-sleeved white button-up shirts (worn with the sleeves rolled up), flannel trousers, and ties. This attire presented problems for ease of play and comfort.

René Lacoste, the French 7-time Grand Slam tennis champion, decided that the stiff tennis attire was too cumbersome and uncomfortable. He designed a white, short-sleeved, loosely-knit piqué cotton (he called the cotton weave jersey petit piqué) shirt with an unstarched, flat, protruding collar, a buttoned placket, and a longer shirt-tail in back than in front (known today as a "tennis tail"; see below), which he first wore at the 1926 U.S. Open championship. Beginning in 1927, Lacoste placed a crocodile emblem on the left breast of his shirts, as the American press had begun to refer to him as "The Crocodile", a nickname which he embraced.

Ralph Lauren (born Ralph Lifshitz, October 14, 1939) is an American fashion designer and business executive; best known for his Polo Ralph Lauren clothing brand.

Ralph Lauren was born Ralph Lifshitz in the Bronx, New York, to Ashkenazi Jewish immigrants, from Pinsk, Belarus: Fraydl (née Kotlar) and Frank Lifshitz, a house painter.

Ralph attended the Salanter Academy Jewish Day School followed by MTA (now known as the Marsha Stern Talmudical Academy), before eventually graduating from DeWitt Clinton High School in 1957. In MTA Lauren was known by his classmates for selling ties to his fellow students. In a moment of spontaneity, when asked what he wanted to do in his Clinton yearbook he stated under his picture that he wanted to be a millionaire. During the summer, Ralph attended Camp Roosevelt (Monticello).

At the age of 16, Ralph's brother Jerry (who was his guardian) changed their last name to Lauren to avoid the unfortunate obscenity reference Lifshitz has in English (although Ralph's brother Lenny retained the name). Apparently Ralph was teased about it in school. “My given name has the word shit in it,” he told Oprah Winfrey. “When I was a kid, the other kids would make a lot of fun of me. It was a tough name. That's why I decided to change it. Then people said, "Did you change your name because you don't want to be Jewish?" I said, "Absolutely not. That's not what it's about. My cousins who lived in California had changed their last name to Lawrence. So I just thought, "I'm going to pick a nice last name"—it wasn't particularly connected to anything or anyone."