Yolillal is a district of the Upala canton, in the Alajuela province of Costa Rica.

The name means a place with an abundant yollillo, a plant.

Yolillal was created on 26 November 1980 by Decreto Ejecutivo 12092-G.

Yolillal has an area of 139.54 km and an elevation of 39 metres.

Historical population

Census	Pop.	±% p.a.
1984	2,728	—
2000	3,019	+0.64%
2011	3,308	+0.83%
2022	4,145	+2.07%
Source: Instituto Nacional de Estadística y Censos Centro Centroamericano de Población

For the 2011 census, Yolillal had a population of 3,308 inhabitants.

The district is covered by the following road routes:

• National Route 4
• National Route 138
• National Route 731