Llano is a rural barrio in the municipality of Guayanilla, Puerto Rico. Its population in 2010 was 773.
Llano has of land area and no water area. In 2010, its population was 773 with a population density of .
Llano was in Spain's gazetteers until Puerto Rico was ceded by Spain in the aftermath of the SpanishâÂÂAmerican War under the terms of the Treaty of Paris of 1898 and became an unincorporated territory of the United States. In 1899, the United States Department of War conducted a census of Puerto Rico finding that the combined population of Llano and Quebradas barrios was 977.