Portoroz is a Slovenian Adriatic seaside resort and spa town located in the Municipality of Piran in southwestern Slovenia. Its modern development began in the late 19th century with the vogue for the first health resorts. In the early 20th century Portoroz became one of the grandest seaside resorts in the Adriatic, along with Abbazia, Lido and Grado, then as part of the Austrian Littoral. It is now one of Slovenia's major tourist areas. Located in the centre is the Palace Hotel, once one of the most important resorts for the Austro-Hungarian monarchy, and currently one of the finest hotels between Venice and Dubrovnik.

The settlement and its surrounding areas are served by Portoroz International Airport which is located in the nearby village of Secovlje.

In the second half of the 19th century, the leaders of the Pirano municipality and local doctors decided to stimulate tourism in the region, by offering health treatment by concentrated salt water and salina mud. From 1879 onward, Dr Giovanni Lugnano the first to offer such treatment to various visitors.

In 1885, after several years of successful start of a new branch of industry, constructions of new complexes and villas began, and, in 1890, the predecessor of the famous Hotel Palace was built.

In 1908, Orazio Pupini, a prominent Austrian doctor with a notable treatment history opened a sanatorium. He was also the main doctor of the Austrian Railways, and a member of the Austrian Doctors' Association. In 1902, the Parenzana railway system was introduced which increased the popularity of the region, but was later dissolved because of decreased interests.

In 1909, the era of construction of private villas ended with opening of a much bigger building for standards at the time; the Palace Cur Hotel, later known as the Palace Hotel. At the initial opening ceremony, in 1910, the Palace Hotel was named "the most beautiful hotel on the Adriatic coast". The hotel was equipped with the most modern therapeutic accessories, and a casino was built for important guests.

The thriving community was halted by World War I, and a few years after the war (in which they came under Italian rule) in 1928 they included a new electric therapy among their treatment programmes. In the interwar period the settlement was slowly regaining its former glory when World War II severely crippled it again. The crisis lasted until 1968 when renovations and new constructions under the new entity of Yugoslavia began to take place along the whole region. In this time they began to build the settlement's infrastructure with the casino doing the bulk of the investments in reconstructing the sports airfield in nearby Secovlje and building the multi-purpose auditorium in 1972.

In 1976, two hotel complexes were constructed in Bernardin; in the following year another was added in the same area. In the same year they began transforming the Lucija saltworks into a marina for smaller vessels. Since the secession of Slovenia from Yugoslavia, Portoroz has become one of the most important tourist sites in the country.