Final answer:
The emperor who rebuilt the Pantheon after it was destroyed by fire was Hadrian.
Step-by-step explanation:
The emperor who rebuilt the Pantheon in Rome after it was destroyed by fire was Hadrian. The original Pantheon, built by Agrippa, was damaged by fire around 80 CE and restored to some extent by Emperor Domitian. However, when it was more substantially damaged by fire again in 110 CE, Emperor Trajan initiated the rebuilding project, which was later completed by his successor, Hadrian, between 125 and 128 CE.