In 2012 the population of the city was 140,473 inhabitants, making it the second most populous municipality in the province of Málaga and the eighth in Andalusia.It is one of the most important tourist cities of the Costa del Sol and throughout most of the year is an international tourist attraction, due mainly to its climate and tourist infrastructure.

However, no remains have been found of any significant settlement, although some artefacts of Phoenician and later Carthaginian settlements have been unearthed in different parts of the municipality, as in the fields of Rio Real and Cerro Torrón.

The existence of a Roman population centre in what is now the El Casco Antiguo (Old Town) is suggested by three Ionic capitals embedded in one section of the Murallas del Castillo (Moorish castle walls), the reused materials of a building from earlier times.

The population is concentrated in two main centres: Marbella and San Pedro Alcántara; the rest is scattered in many developments in the districts of Nueva Andalucia and Las Chapas, located along the coast and on the mountain slopes.

According to a study by the Association of Municipalities of the Costa del Sol, based on the production of solid waste in 2003, Marbella had a population of about 246,000 inhabitants, almost twice that of the population census of 2008.

Marbella is situated on the Mediterranean Sea, between Málaga and the Strait of Gibraltar, in the foothills of the Sierra Blanca.

The municipality covers an area of 117 square kilometres (45 sq mi) crossed by highways on the coast, which are its main entrances.

The coastline is heavily urbanised; most of the land not built up with golf courses has been developed with small residential areas. Marbella is bordered on the north by the municipalities of Istán and Ojén, on the northwest by Benahavís, on the west by Estepona and on the northeast by Mijas. The Sierra Blanca is most centrally located in the province, looming over the old village.

This mountain range has three peaks: La Concha, located further west at 1,215 m above sea level, Juanar Cross, located eastward (within the municipality of Ojen) at 1,178 m above sea level, and the highest, Mount Lastonar, located between the two at 1,270 metres.

Since the mid-1950s, however, Marbellan residents have been called "marbellís" or "marbellíes", the only gentilic, or demonym, that appears in the Diccionario de la Lengua Española (Dictionary of the Spanish Language) published by the Royal Spanish Academy.