Sertã (Portuguese pronunciation: [sɨɾˈtɐ̃] ) is a municipality in Castelo Branco District in Portugal. The population in 2011 was 15,880, in an area of 446.73 km.

The present mayor is José Farinha Nunes, elected by the PSD. The municipal holiday is the June 24.

Population of Sertã (1801 – 2011)
1801	1849	1900	1930	1960	1981	1991	2001	2011
10235	13456	20380	24057	27997	21503	18199	16720	15880

Local sports club: Sertanense Futebol Clube (mainly devoted to soccer, playing (2004-2005) the 3rd Division Championship).

Local newspaper: A Comarca da Sertã (weekly)

Administratively, the municipality is divided into 10 civil parishes (freguesias):

Parish name	Population (2011)	Area km
Cabeçudo	957	10.39
Carvalhal	465	10.02
Castelo	1,046	24.57
Cernache do Bonjardim, Nesperal e Palhais	3,625	101.58
Cumeada e Marmeleiro	731	51.73
Ermida e Figueiredo	423	42.74
Pedrógão Pequeno	753	36.86
Sertã	6,196	80.95
Troviscal	864	53.37
Várzea dos Cavaleiros	820	34.51

• Nuno Álvares Pereira (born 1360 in Cernache de Bonjardim - 1431) a Portuguese general, he became a mystic and was beatified by Pope Benedict XV, in 1918, and canonised by Pope Benedict XVI in 2009
• João Castel-Branco Goulão (born 1954 in Cernache do Bonjardim) a physician and the current national drug coordinator for Portugal