Isona i Conca Dellà (Catalan pronunciation: [iˈzonɛj ˈkoŋkɛ ðaˈʎa]) is a municipality in the comarca of the Pallars Jussà in Catalonia, Spain. It is situated in the valley of the Conques river in the south-east of the comarca. It was formed in 1970 by the fusion of the following municipalities: Isona, Basturs, Benavent de la Conca, Biscarri, Conques, Covet, Gramenet, Llordà, Masos de Sant Martí, Montodó, Orcau i Figuerola d'Orcau, Sant Romà d'Abella and Siall. The town hall is in Isona. The municipality is served by the C-1412 road between Artesa de Segre and Tremp, and is linked to Coll de Nargó by the L-511. It includes a small exclave to the south.

The church of Santa Maria in Covet and Llordà castle are protected historico-artistic monuments.

The municipality of Isona and Conca Dellà is formed of fourteen villages. Populations are given as of 2005:

• Basturs (40), three kilometres south-east of Orcau
• Benavent de la Conca (26), at the foot of a 200 m hill of conglomerate
• Biscarri (53), at the foot of the Moles range at the edge of the Tremp basin
• Conques (98)
• Covet (5)
• Figuerola d'Orcau (181)
• Gramenet (1)
• Isona (619)
• Llordà (10)
• Els Masos de Sant Martí
• Montadó (3)
• Orcau (18)
• Sant Romà d'Abella (89)
• Siall (6)

Populations from before 1970 are the totals of the populations of the former municipalities.

1900	1930	1950	1970	1986	2007
3522	2695	2257	1615	1502	1153

• Panareda Clopés, Josep Maria; Rios Calvet, Jaume; Rabella Vives, Josep Maria (1989). Guia de Catalunya, Barcelona: Caixa de Catalunya. ISBN 84-87135-01-3 (Spanish). ISBN 84-87135-02-1 (Catalan).

• Official website (in Catalan)
• Government data pages (in Catalan)