Caddebostan is a neighbourhood in the Kadıköy district inside the city of Istanbul, Turkey. It has a population of 20,170 (2023). The 1.663 km² Caddebostan is bordered by the neighbourhoods of Fenerbahçe in the west, Göztepe and Erenköy in the north, and Suadiye in the east. Modern day Caddebostan roughly corresponds to the ancient Byzantine town, Rouphinianai.

Previously a summer resort place with only mansions used as summer houses and a dock, Caddebostan is currently a residential and attractive area for the shopping and eating possibilities it offers, especially on the Bağdat Avenue. Aside from the busy shopping street, the Caddebostan Coast is the neighbourhood's coast where people can walk, ride a bike and enjoy facilities the Dalyan Park on the coast has to offer such as sport fields and playgrounds. It is also possible to see some historical mansions like the Ragıp Pasha Mansion situated on the coast.

In recent years, Caddebostan has received a great amount of popularity for its location near the sea and its high development, with people starting to move to the neighbourhood to "escape" the "more crowded" European side of Istanbul. This led to the area surrounded by Baghdad Street suffering from traffic and overcrowdedness.

In the Byzantine period, Rouphinianai (also spelled Ruphinianus), or Drys refers to Caddebostan and the surrounding area. Rouphinianai was a port town presumed to have been located about 5 kilometers east of Chalcedon. The settlement had a harbor, dock, palace and several religious buildings. The town took its name from ruler Flavius Rufinus, while the name Drys likely comes from a magnificently large oak tree spotted in or near the area as Drys has a similar meaning to oak.

In the Ottoman times, Caddebostan was referred to as Cadı Bostanı ("witch garden"), as outlaws commonly hid in the neighborhood. In 1906, the Ragıp Pasha Mansion was built by August Jasmund who also constructed the Sirkeci railway station. In the Republic era of Turkey, when the neighborhood became more developed, with a dock opening on the shore, the name was changed to Caddebostan, which literally translates to "street garden".

In 1930, a separate neighborhood unit was created for Caddebostan, separating it from Erenköy and Göztepe. The neighborhood became a place for entertainment with its beaches and a casino opening in the 40's. (Currently, the casino is closed.) In the 60's, Caddebostan and the surrounding area started rapidly urbanizing. In 1985, the Caddebostan Coast was filled which increased Caddebostan's popularity further, though this led to the closure of the dock.

While Caddebostan is a small neighbourhood in terms of size, it has many schools; both public and private. These private schools include Irmak Schools and İSTEK Semiha Şakir Schools.

There is a cultural center, CKM, short for Caddebostan Kültür Merkezi (Caddebostan Cultural Center in English) located in Caddebostan. The place includes one theater hall, many movie theaters and other facilities such as a gym, a bookshop, a library, and a bar.

Caddebostan has the very popular Caddebostan Coast which people often walk, run, or cycle by the cycling routes. There are often events organized on the coast, several of them sponsored by Red Bull. The coast is approximately 950 meters long. The Caddebostan Coast also includes the three Caddebostan Beaches. The coast includes the Dalyan Park which contains facilities such as playgrounds and sport related installments. It is possible to swim in the waters of Caddebostan unlike most places in Istanbul (due to pollution). In the summer, it gets very crowded.

There are many old mansions on the coast, the most significant one being Ragıp Pasha Mansion, also referred as "Perili Köşk". The mansion carries historical legacy and is the landmark of Caddebostan. Some other mansions include Theron Damon Mansion, Cemil Topuzlu Mansion and Tevhide Hanım Mansion.

Caddebostan, in its borders holds one of the most important and active parts of Bağdat Avenue which most famous luxury brands are located on. The entire street is 14 kilometers long, spanning from Maltepe in the east to Kadıköy in the west. There is often a lot of traffic and the street is usually crowded. It is the main shopping center of the neighbourhood.

Along with Bağdat Avenue, another important street in Caddebostan is İskele Street, commonly referred to as "Barlar Street", ("bars street"). The street is a place which has many bars (explaining the streets name). At nighttime, Barlar Street is very active, and can be dangerous as it is common to see fights and other incidents.

The Göztepe 60. Year Park stretches from Bağdat Street to the coast, roughly between Göztepe and Caddebostan. The park is a popular and often crowded place which many parents commonly take their children to play or just to walk around and relax. Göztepe Park contains exercise areas, flower gardens, and playgrounds. It is a quite big park and attracts various people in the region.