Rómendacil II was a fictional character in J. R. R. Tolkien's universe of Middle-earth

He was the son of King Calmacil, the second son of King Atanatar II Alcarin and was originally named Minalcar.

He was born in the last year of the long reign of Hyarmendacil I as Minalcar and he rose to a powerful position early because his uncle Narmacil I (first son of Atanatar II) felt uncomfortable with the Kingship.

He was Regent from 1240 T.A. and struck a decisive blow against the Easterlings whom he defeated near the Sea of Rhûn. He also fortified Gondor and made pacts with the Northmen of Rhovanion, all before he took the throne. After Narmacil's death, he remained Regent for ten years under his father Calmacil.

When he finally ascended to the throne after the death of his father, he immediately took the name Rómendacil, the East-victor, as his distant forefather Tarostar had done.

He was responsible for the Argonath, the pillars of the Kings. They were known to stand above Nen Hithoel far into the Fourth Age and appear prominently in The Lord of the Rings.

To cement an alliance with the Northmen, Rómendacil II sent his son Valacar as an ambassador. While Valacar was on his mission he married Vidumavi, the daughter of Vidugavia, the King of Rhovanion, which would ultimately lead to the disastrous Kin-strife.

Rómendacil died in 1366 T.A. and was succeeded by Valacar.