A Miocene (Burdigalian) carbonate platform in Northern Sardinia was studied in order to unravel its facies and stratigraphic architecture. The Sedini Limestone unit formed at the western margin of the Pèrfugas sub‐basin on a fault‐bounded topographic high. The 10–60 m sedimentary succession contains two depositional sequences separated by a major erosional unconformity, and several high‐frequency sequences reflecting the occurrence of higher‐order base‐level fluctuations. The deposits are massive limestones, bedded limestones and marlstones, which form a carbonate platform with an extension of about 19km2. Sequence 1 consists of a homoclinal ramp with beaches, minor patch reefs, longshore bars, and finer‐grained outer‐ramp sediments. Sequence 1 deposits were formed by a warm temperate carbonate factory with abundant coralline algae, frequent larger benthic foraminifera (Heterostegina, Amphistegina, Borelis), barnacles, bryozoans, molluscs, and minor corals. Sequence 2 documents a steepening of the carbonate platform slope. In the lower part of this sequence, a belt of submarine dunes separated the platform‐interior from deeper water bioclastic deposits. Dunes were locally stabilized by coralline algal bindstones. In the upper part of Sequence 2, the depositional system consisted of an extensive reef flat with a marked slope break formed by coralline algal bindstones and rhodolithic clinoform beds dipping at up to 27°. The carbonate factory of Sequence 2 is rich in reef‐building zooxanthellate corals and therefore can be unequivocally assigned to a tropical carbonate factory. Spectacular outcrops in the Sedini Limestone unit allow a detailed observation of the facies, the bedding geometries, and the stratigraphic architecture of carbonates formed at the transition from the temperate to the tropical realm.