Oscar Arnold Wergeland (12 October 1844 – 20 May 1910) was a Norwegian painter. He is best known for his historical painting of the Constituent Assembly at Eidsvoll (Riksforsamlingen på Eidsvoll 1814). Two of his paintings are located in the National Gallery of Norway.

His parents were Sverre Nicolai Wergeland (1817–1896) and Anne Margrethe Larsen (1817–1889). His sister was Agnes Mathilde Wergeland (1857–1914), who emigrated to the United States and became known as an author. He was the great-nephew of Nicolai Wergeland, a Norwegian priest, writer, and politician, and a member of the Norwegian Constituent Assembly at Eidsvoll. Hence Henrik Wergeland, Camilla Collett, and Joseph Frantz Oscar Wergeland were cousins of his father.
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