The Forum of Caesar, also known by the Latin Forum Iulium or Forum Julium, Forum Caesaris, was a forum built by Julius Caesar near the Forum Romanum in Rome in 46 BC.

Caesar decided to construct a forum bearing his name in the northeast section of the Forum Romanum, and purchased some very expensive parcels of land in that area (the final cost was said to be 100,000,000 sesterces). Forum construction began probably in 51 BC, although Cicero and Gaius Oppius were entrusted with purchasing the parcels of land on Caesar's behalf as early as 54 BC. On the eve of the Battle of Pharsalus in 48, Caesar vowed a temple to Venus Victrix, the legendary progenitor of his own clan, the gens Iulia. This original dedication was done because she was Pompey's favourite goddess, and Caesar hoped to gain the goddess's favour before the battle against Pompey.^{[citation needed]}

The forum measured 160 x 75 m, stretching from the Argiletum on the southeast side of the Forum Romanum to the Atrium Libertatis. On completion in 46 BC it was dedicated to Caesar and his deeds. As part of the dedication, lavish games were funded by Caesar, indicating the staggering cost and thus the personal interest that Caesar had invested in the project.

Some believe that Augustus furnished the west side with the shops and offices therefore being the one to see its completion.

The Forum of Caesar originally meant an expansion of the Forum Romanum. The Forum, however, evolved so that it served two additional purposes. As Caesar became more and more involved in this project, the Forum became a place for public business that was related to the Senate in addition to a shrine for Caesar himself as well as Venus Genetrix.

Before his assassination, Caesar would have the Senate meet him before his temple, an act deemed very unpopular by the Senate. The Forum of Caesar also had an effect on the Curia, which Caesar began to reconstruct in 44 BC. This reconstruction moved the Forum of Caesar much closer to the Curia. The ten tabernae located on the western side of the Forum and its now close approximation to the Senate house symbolized the unity that Caesar felt between himself and the Senate.

Caesar also placed a statue of his favourite horse in front of the temple. Following his assassination, a statue of Caesar riding this horse was added. Caesar (gens Julia) claimed descent from Venus through his ancestor Julus. The Temple of Venus Genetrix was completed after Caesar's assassination by Roman senators, which included lavish games in reference to Caesar's original dedication of the Forum. The temple was re-built after the removal of the gap between the Capitoline Hill and the Quirinal Hill, under the reigns of Domitian and Trajan; during the adaptation of the gap, a second floor of tabernae was created behind the west portico of the square and a building with pillars made of tuff blocks, named Basilica Argentaria, was erected. The new temple was inaugurated in the same day as the Trajan's Column, on May 12, 113, as attested by an inscription in the Fasti Ostienses.

In the plaza of the forum, Caesar allowed a statue of himself wearing a cuirass to be set up, and also set up an equestrian statue of himself seated on a horse with feet carved like those of a human, according to Pliny the Elder. In the time of Hadrian, and perhaps earlier, a fountain with three basins connected by low walls was set in front of the temple, with a statue of the Empress Vibia Sabina placed on a base adjacent to it.