Judaea was a Roman province from 6 to 135 CE, which at its height encompassed the regions of Judea, Idumea, Peraea, Samaria, and Galilee, as well as parts of the coastal plain of the southern Levant. At its height, it encompassed much of the core territories of the former Kingdom of Judaea, which had been ruled by the Hasmonean and Herodian dynasties in previous decades. The name Judaea (like the similar Judea) derives from the Iron Age Kingdom of Judah, which was centered in the region of Judea.

Since the Roman Republic's conquest of Judaea in 63 BCE, which abolished the independent Hasmonean monarchy, Rome maintained a system of semi-autonomous vassalage in the region. After Hasmonean ruler Antigonus II Mattathias briefly regained the throne, he was overthrown by Herod, who was appointed King of the Jews by the Roman Senate and ruled Judaea until his death in 4 BCE. The province's formal incorporation into the Roman Empire was enacted by Augustus in 6 CE, following an appeal by the populace against the misrule of Herod's son, Herod Archelaus (r. 4 BCE – 6 CE). The administrative capital was relocated from Jerusalem to the coastal city of Caesarea Maritima.

Over the six decades following the province's establishment, relations between the majority Jewish population and Roman authorities were marked by frequent crises. With the onset of direct rule, the official census instituted by Publius Sulpicius Quirinius, the governor of Roman Syria, caused tensions and led to an uprising by Jewish rebel Judas of Galilee (6 CE). Other notable events in the region include the crucifixion of Jesus c. 30–33 CE (which led to the emergence of Christianity) and in 37 CE, Emperor Caligula ordered the erection of a statue of himself in the Second Temple. A brief respite came under Agrippa I (r. 41–44 CE), a popular ruler who temporarily restored Jewish self-governance under Roman auspices. However, after his death, Judaea—now encompassing Galilee and Peraea—reverted to direct Roman rule, and unrest gradually escalated. In the following years, prophetic figures sought to gain followers, Sicarii assassins targeted officials, and corrupt and brutal governors—most notably Gessius Florus (r. 64–66 CE)—further inflamed tensions.

In 66 CE, unrest in Caesarea, followed by clashes in Jerusalem, ignited the First Jewish–Roman War. The Romans, under Vespasian and later his son Titus, systematically crushed the rebellion, culminating in the razing of Jerusalem and the destruction of the Second Temple in 70 CE. The Jewish population recovered within a generation and, in 132 CE, launched the Bar Kokhba revolt in response to Hadrian's plans to construct Aelia Capitolina, a non-Jewish colony, on the ruins of Jerusalem. The rebels briefly established an independent Jewish state, but the Roman suppression of the revolt resulted in the widespread destruction and near-depopulation of the region of Judea. In that same year, Judea was officially merged with Galilee in an enlarged province named Syria Palaestina.

Judaea, an independent state under the Hasmonean dynasty, was conquered by the Roman Republic in 63 BCE. At the time, it was embroiled in a civil war between Hyrcanus II and Aristobulus II, sons of Queen Salome Alexandra, both vying for the throne. Roman general Pompey intervened, besieging and capturing Jerusalem. In the aftermath, he appointed Hyrcanus II as ethnarch and High Priest, but denied him the title of king.

In 40 BCE, Antigonus II Mattathias, son of Aristobolus II, temporarily reclaimed the throne with Parthian support but was overthrown in 37 BCE by Herod, whom the Roman Senate had appointed "King of the Jews." Herod ruled Judaea as a client kingdom of Rome until his death in 4 BCE. Widely despised and resented by the public, he maintained close relations with the Romans. During this period, the remaining Hasmonean heirs were eliminated, and the grand port city of Caesarea Maritima was constructed.

Herod died in 4 BCE, and his kingdom was partitioned into a tetrarchy and divided among three of his sons. Archelaus served as ethnarch of Judea (including Jerusalem), Samaria, and Idumaea, while Herod Antipas governed Galilee and Peraea, and Philip ruled over Gaulanitis, Trachonitis and Batanaea. Archelaus rule of Judea was gravely atrocious that he was dismissed in 6 CE by the first Roman emperor, Augustus, after an appeal from his own subjects. Following his removal, Judaea was annexed as the Roman province of Judaea. Herod Antipas continued to rule Galilee and Peraea until his dismisal by Emperor Caligula in 39 CE.

Following the death of Herod the Great, the Herodian Kingdom of Judea was divided into the Herodian Tetrarchy, jointly ruled by Herod's sons and sister: Herod Archelaus (who ruled Judea, Samaria and Idumea), Herod Philip (who ruled Batanea, Trachonitis as well as Auranitis), Herod Antipas (who ruled Galilee and Peraea) and Salome I (who briefly ruled Jamnia).