A taxi dancer is a paid dance partner in a ballroom dance. Taxi dancers work (sometimes for money but not always) on a dance-by-dance basis. When taxi dancing first appeared in taxi-dance halls during the early 20th century in the United States, male patrons typically bought dance tickets for a small sum each. When a patron presented a ticket to a chosen taxi dancer, she danced with him for the length of a song. She earned a commission on every dance ticket she received. Though taxi dancing has for the most part disappeared in the United States, it is still practiced in some other countries.

The term "taxi dancer" comes from the fact that, as with a taxi-cab driver, the dancer's pay is proportional to the time they spend dancing with the customer. Patrons in a taxi-dance hall typically purchased dance tickets for ten cents each, which gave rise to the term "dime-a-dance girl". Other names for a taxi dancer are "dance hostess" and "taxi" (in Argentina). In the 1920s and 1930s, the term "nickel hopper" gained popularity in the United States because out of each dime-a-dance, the taxi dancer typically earned five cents.

Taxi dancing traces its origins to the Barbary Coast district of San Francisco which evolved from the California Gold Rush of 1849. In its heyday the Barbary Coast was an economically thriving district, inhabited mostly by men, that was frequented by gold prospectors and sailors from all over the world. That district created a unique form of dance hall called the Barbary Coast dance hall, also known as the Forty-Nine ['49] dance hall. Within a Barbary Coast dance hall female employees danced with male patrons, and earned their living from commissions paid for by the drinks they could encourage their male dance partners to buy.

Still later after the San Francisco Earthquake of 1906 and during early days of jazz music, a new entertainment district developed in San Francisco and was nicknamed Terrific Street. And within that district an innovative dance hall, The So Different Club, implemented a system in which customers could buy a token which entitled them to one dance with a female employee. Since dancing had become a popular pastime, many of the So Different Club's patrons went there to see and learn the latest new dances.

In 1913, San Francisco enacted a law against dancing in any café or saloon where alcohol was served. The closure of the dance halls on Terrific Street fostered a new kind of pay-to-dance scheme, called a closed dance hall, which did not serve alcohol. The name was derived from the fact that female customers were not allowed; the only women permitted in these venues were female employees. The closed dance hall introduced the ticket-a-dance system, which became the centerpiece of the taxi-dance-hall business model. A taxi dancer earned her income from the tickets she received for dances.

Taxi dancing then spread to Chicago, where dance academies, which were struggling to survive, began to adopt the ticket-a-dance system for their students. The first instance of the ticket-a-dance system in Chicago occurred at Mader-Johnson Dance Studios. The dance studio's owner, Godfrey Johnson, describes his innovation:

I was in New York during the summer of 1919, and while there visited a new studio opened by Mr. W___ W___ of San Francisco, where he had introduced a ten-cent-ticket-a-dance plan. When I got home I kept thinking of that plan as a way to get my advanced students to come back more often and to have experience dancing with different instructors. So I decided to put a ten-cent-a-lesson system in the big hall on the third floor of my building ... But I soon noticed that it wasn't my former pupils who were coming up to dance, but a rough hoodlum element from Clark Street ... Things went from bad to worse; I did the best I could to keep the hoodlums in check.

This system was so popular at dance academies that the taxi-dance system quickly spread to an increasing number of non-instructional dance halls.