Alfonso II of Aragon (Alfons I of Provence and Barcelona, 1152-1196), known as the Chaste or the Troubadour was king of Aragon and count of Barcelona from 1162 to 1196. He was the son of Ramon Berenguer IV of Barcelona and Petronila of Aragon.

Born Ramon Berenguer, he ascended the united thrones of Aragon (1164) and Barcelona (1162) as Alfonso, changing his name in compliment to the Aragonese, to honor King Alfonso I of Aragon. He was the first ruler to be both king of Aragon and count of Barcelona. He was also Count of Provence from 1181 to 1185.

For most of his reign he was allied with King Alfonso VIII of Castile, both against Navarre and against the Moorish taifa kingdoms of the south. In his Reconquista effort Alfonso pushed as far as Teruel, conquering this important stronghold on the road to Valencia in 1171. The same year saw him capturing Caspe.

Apart from common interests, kings of Aragon and Castile were united by a formal bond of vassalage the former owed to the latter. Besides, on January 18, 1174 in Saragossa Alfonso married infanta Sancha of Castile, sister of the Castilean king.

Another milestone in this alliance was a formal treaty the two kings concluded at Cazorla in 1179, delineating zones of conquest in the south along the watershed of rivers Júcar and Segura. Southern areas of Valencia including Denia were thus secured to Aragon.

During his reign Catalonian influence north of the Pyrenees reached its zenith. His realms incorporated not only Provence, but also the counties of Cerdanya and Roussillon (inherited in 1172). Béarn and Bigorre paid hommage to him in 1187. Alfonso's involvement in the affairs of Languedoc, which will cost the life of his successor, Peter II of Aragon, for the moment proved highly beneficial, strengthening Catalonian trade and stimulating emigration from the north to colonise the newly reconquered lands in Aragon.

King Alfonso died in 1196. He was a noted poet of his time and a close friend of King Richard the Lionheart.

Alfonso's marriages and descendants
• Wife, Sancha of Castile, daughter of king Alfonso VII of Castile, b. 1155 or 1157, d. 1208
• Constança -> married King Imre of Hungary and later, Frederick II, Holy Roman Emperor
• Leonor -> married Count Raymond VI of Toulouse
• Peter II of Aragon (I of Barcelona), b. 1174, killed at the Battle of Muret, September 12, 1213
• Dolça (nun)
• Alfonso II, Count of Provence, b. 1180, d. 1209
• Fernando, Abbot of Montearagon, d. after 1227
• Ramon Berenguer, d. in the 1190s