Mathias Otto Leth Sommerhielm was a Norwegian politician.

He served as First Minister in Kristiania from 1815 to 1822, a position assigned to the most prominent cabinet minister at the time. In 1822, he became Prime Minister of Norway, office located in Stockholm. He held the office until 1827, when the seat was vacated. In the period 1878–1924, Kristiania was the name used for Norways capital Oslo (having been called Christiania since 1624). ... The Battle of New Orleans 1815 was a common year starting on Sunday (see link for calendar). ... 1822 was a common year starting on Tuesday (see link for calendar). ... This is a list of Viceroys (Rigsstatholder) and Prime Ministers (statsminister) of Norway. ...   Stockholm? is the capital and the largest city in Sweden. ... 1827 was a common year starting on Monday (see link for calendar). ...