Pasodoble (Spanish: double step) is a fast-paced Spanish military march used by infantry troops. Its speed allowed troops to give 120 steps per minute (double the average of a regular unit, hence its name). This often was accompanied by a marching band, and as a result of that, the military march gave rise to a modern Spanish musical genre and partner dance form. Both voice and instruments, as well as the dance then began to develop and be practiced independently of marches, and also gained association with bullfighting due to the genre being popular as an instrumental music performed during bullfights.

Both the dance and the non-martial compositions are also called pasodoble.

All pasodobles have binary rhythm. Its musical structure consists of an introduction based on the dominant chord of the piece, followed by a first fragment based on the main tone and a second part, called "the trío", based on the sub-dominant note, based yet again on the dominant chord. Each change is preceded by a brieph. The last segment of the pasodoble is usually "the trío" strongly played. The different types of pasodoble – popular, taurino, militar – can vary in rhythm, with the taurine pasodobles being the slowest and the popular being faster and often incorporating voice. Pasodoble as we know it started in Spain but is now played in a wide variety of Hispanic nations. Each region has developed its own subgenre and personal style of pasodoble, adjusting some formal aspects of the structure to fit their local musical tradition. In modern Spain, the most prolific composition of pasodobles takes place on the Valencian coast, associated to the festivals of Moors and Christians and the Fallas.

The dance form is very free regarding figures. The dancers must remain one in front of the other, and keep their bodies parallel to each other at all times, leaning slightly to the left. They must give one step per tempo. The left hand of the male and the right hand of the woman must remain united almost permanently. Besides this, almost all motions and figures are accepted, which allows space for dramatization. The dance can be similar to the one-step, except for the speed and number of steps given.

The origin of this form of music is disputed.

The facts known about it from historical evidence are that it was written as early as the 18th century, since Spain has pasodoble scores dating back to 1780; that it was incorporated into comedies and adopted as a regulatory step for the Spanish infantry; and that the music was not introduced into bullfights until the 19th century.

One hypothesis suggests, based on the etymology of the name, that it comes from the French "pas-redouble", a form of speedy march of the French infantry during the late 18th century. It is claimed to have both Spanish and French characteristics. The modern steps often contain French terms, but the dance resembles the nature of the bullfight. It is said to have emerged from southern French culture during the 1930s. Supporters of this hypothesis, mostly French musicologists, suggested that pasodoble was a way for the French to portray the techniques used in Spanish bullfights. This hypothesis neglects to explain the presence of scores dating from 1780, that Spanish infantry already marched at double speed before the French army did and French musicologist usually refers the bullfight-related movements or themes, peculiarity that does not make sense since in Spain it was associated with bullfighting a long time later.

In the United States of America it became popular only as a dance in the 1930s, in the form performed under the vision of the French ballroom dance schools, which associated this Spanish music with what in France was very stereotypically associated with Spanish traditions and bullfighting, so is viewed as a french ballroom dance instead of a spanish military march.