Obernai is a commune in the Bas-Rhin department in Alsace in north-eastern France. It lies on the eastern slopes of the Vosges mountains.

Obernai is a rapidly growing city, its number of inhabitants having gone up from 6,304 in 1968 to 11,099 in 2006. The metropolitan area of Obernai had 12,369 inhabitants in 2006, from 7,293 in 1968.

Places to visit include:

• domain of the Léonardsau (19th century - early 20th century): current museum of the horse and the horse carriage.
• Truttenhausen abbey (in ruins): old monastery of the regular canons of St-Augustin (15th century).
• Gail Castle (1826-27): Currently the Freppel High School
• Oberkirch Castle: rebuilt between 1843 and 1846 with the characteristics of an older fortified castle of the 16th or 17th century.
• El Biar Castle: Built between 1864 and 1865 on the site of an old flour mill, by General de Vives (1802, 1884); it is named after a residential section of Algiers.
• Old six-bucket well (1579)
• Clocktower (Kappelturm)
• Wheat Market (Halle aux Blés)
• Romanesque house in the rue des Pélerins
• Old Synagogue