← 1839 1838 1837 1840 in Portugal → 1841 1842 1843
Centuries:	17th 18th 19th 20th 21st
Decades:	1820s 1830s 1840s 1850s 1860s
See also:	List of years in Portugal

Events in the year 1840 in Portugal.

Incumbents

• Monarch: Mary II
• Prime Minister: José Travassos Valdez, 1st Count of Bonfim

Births

• 8 July – Manuel de Arriaga, lawyer and politician (died 1917)

Deaths

• 7 September — Luís do Rego Barreto, military and colonial administrator (b. 1777).^[1]