Riolos

{{Infobox Greek Dimos

|name = Riolos

|name_local = Ρίολος

|type = community

|periph = West Greece

|periphunit = Achaea

|municipality = West Achaea

|municunit = Larissos

|pop_community = 494

|population_as_of = 2021

|area =

|elevation = 100

|coordinates = {{coord|38|01|N|21|28|E|format=dms|display=inline,title}}

|postal_code = 270 52

|area_code = 26930

|licence =

|website =

|image_skyline =

|caption_skyline =

|elevation_min =

|elevation_max =

}}

Riolos ({{langx|el|Ρίολος}}) is a village and a community in the municipal unit of Larissos, Achaea, Greece. It is located on the northwestern edge of the Movri hills, 4 km north of Mataragka, 3 km southwest of Krinos, 6 km southeast of Lappas and 32 km southwest of Patras. The community includes the small village Mazaiika. The river Larissos flows southwest of the village. During the Greek War of Independence a battle took place in Riolos in which the Greeks, led by Thallis Theodoridis the Elder, were victorious.