Rize Province (Turkish: Rize ili) is a province of northeast Turkey, on the eastern Black Sea coast between Trabzon and Artvin. The province of Erzurum is to the south. Its area is 3,835 km², and its population is 344,016 (2022). The capital is the city of Rize. It was formerly known as Lazistan, however the designation of the term of Lazistan was officially banned in 1926.

The province is home to Turkish, Laz, Hemshin and Georgian communities.

The name comes from Greek ρίζα (riza), meaning "mountain slopes". The Georgian, Laz, and Armenian names respectively are Rize (რიზე), Rizini (რიზინი), and Rize (Ռիզե).

During the medieval era, the region was under Byzantine control, and was mainly populated by Greeks and indigenous Lazs. During the reign of the Byzantine emperor Justinian I (c. 527–565), the tribes of the interior, called Sannoi or Tzannoi, the ancestors of modern Laz people, were subdued, Christianized and brought to central rule. Locals began to have closer contact with the Greeks and acquired various Hellenic cultural traits, including in some cases the language. Locals were under nominal Byzantine suzerainty in the theme of Chaldia, with its capital at Trebizond, governed by native semi-autonomous rulers, like the Gabras family. In 790 AD, Armenians fleeing from the Arab invasion of Armenia settled in Hemshin and established the Principality of Hamamshen. Following the invasion of the Seljuk Turks, there was a larger influx of Armenians in the area, resulting in partial Armenization of the local Tzan population.

With the Georgian intervention in Chaldia and collapse of Byzantine Empire in 1204, the Empire of Trebizond was established along the southeastern coast of the Black Sea, populated by a large Lazian-speaking population. In the eastern part of the same empire, an autonomous coastal theme of Greater Lazia was established. Byzantine authors, such as Pachymeres, and to some extent Trapezuntines such as Lazaropoulos and Bessarion, regarded the Trapezuntian Empire as being merely a Lazian border state. Though Greek in higher culture, the rural areas of Trebizond empire appear to have been predominantly Laz in ethnic composition. Laz family names, with hellenized terminations, are noticeable in the records of the mediaeval empire of Trebizond.

In 1282, the kingdom of Imereti besieged Trebizond, however after the failed attempt to take the city, the Georgians occupied several provinces, and the Trebizontine province of Lazia threw off its allegiance to the king of the 'Iberian' and 'Lazian' tribes and united itself with the Georgian Kingdom of Imereti.

The Laz populated area was often contested by different Georgian principalities. Through the Battle of Murjakheti (1535), the Principality of Guria finally ensured control over the area until 1547, when it was conquered by resurgent Ottoman forces and reorganized into the Lazistan Sanjak as part of eyalet of Trabzon.

From the late-17th century onwards, the Ottoman administration built multiple bridges across the Fırtına River and its tributaries.