Segantini Museum, Cultural property museum in St. Moritz, Switzerland.

The Segantini Museum is an art museum in St. Moritz, Grisons, Switzerland, dedicated to the painter Giovanni Segantini and housed in a purpose-built circular building topped by a wide dome. The round shape of the structure and its bright interior make it one of the most recognizable museum buildings in the Swiss Alps.

The museum was built to plans by architect Nicolaus Hartmann, modelled on the pavilion Segantini had designed for his Engadine panorama at the 1900 Paris World Exhibition. Hartmann shrank the design, added floors and used local rubble stone instead of an iron frame. The driving force was Segantini's friend and physician Oskar Bernhard, who in 1907 conceived the idea in Milan with the art dealer Alberto Grubicy; a committee was formed and the museum was inaugurated on 28 September 1908, the ninth anniversary of the painter's death, and opened in June 1909.

The museum holds the largest collection of works by Giovanni Segantini anywhere in the world, a painter who made mountain life and rural labor the center of his work. Walking through the rooms, visitors can see how closely he observed the people and the light of the high Alps.

The museum sits in the center of St. Moritz and is easy to reach on foot, with signs pointing to the entrance from the main streets. A visit pairs well with a walk around the village, as the building is close to the main roads and shops.

The three panels of the Alpine Triptych are titled Werden, Sein and Vergehen — Becoming, Being and Passing — and the sources disagree on their subjects: the German article assigns Werden the evening meadow at Soglio, Sein the wide view from the Schafberg and Vergehen the snow landscape of Maloja before sunrise, while the Italian article gives the middle panel as La natura. The central panel was sold in 1906 by Grubicy to Prince Wagram in Paris for 160,000 lire and only later reunited with the other two.