The Basilica Porcia was the first known basilica to be built in Rome. It was built in 184 BCE by Marcus Porcius Cato in spite of political opposition.
The location of the building was to the W. of the Curia Hostilia just across the Vicus Lautomiarum from the Mamertine Prison, or Carcer. The modern road Via Tulliana passes the area.
Cato bought the previous buildings on the spot, two private houses and some shops, with his own money to build the basilica. The basilica was used for tribunals and meetings.
The fire that broke out during the funeral of P. Clodius Pulcher in 52 BCE destroyed both the Curia Cornelia and the Basilica Porcia. The basilica was probably never rebuilt, as it is not heard of afterwards.
There is nothing visible left of the Basilica Porcia.