Namesakes
Biblical Characters:
4 characters
Gaius (m) Acts 19:29 
Gaius (m) Acts 20:4
Gaius (m) 3 John 1:1
Gaius (m) Rom. 16:23
Bishops of Rome and the Popes:
1 pope
Caius (a.k.a. Gaius) 283-296
Notable Actors and Entertainers:
1 actor
Gaius Charles 1983-
Notable Military Figures:
1 general
Gaius Julius Caesar 100-44 BC
Notable Philosophers and Thinkers:
2 historians
Sallust (a.k.a. Gaius) 86-c. 35 BC
Suetonius (a.k.a. Gaius) 69-122
Notable Politicians and Statespeople:
3 statespersons, 1 politician
Gaius Julius Caesar 100-44 BC
Gaius Cassius Longinus c. 86-42 BC
Gaius Cilnius Maecenas 70-8 BC
Gaius de Gaay Fortman 1911-1997
Notable Scientists and Inventors:
1 naturalist
Pliny the Elder (a.k.a. Gaius) c. 23-79
Notable Writers:
2 authors, 2 poets
Catullus (a.k.a. Gaius) 84-54 BC
Gaius Helvius Cinna ?-44 BC
Petronius (a.k.a. Gaius) c. 27-66
Pliny the Younger (a.k.a. Gaius) 61-c. 113
Roman and Byzantine Emperors:
10 emperors
Emperor Gaius Julius Caesar 27 BC-14
Emperor Gaius Julius Caesar Germanicus 37-41
Emperor Gaius Julius Verus Maximinus 235-238
Emperor Gaius Messius Quintus Decius 249-251
Emperor Gaius Valens Hostilianus Messius Quintus 251
Emperor Gaius Vibius Trebonianus Gallus 251-253
Emperor Volusian (a.k.a. Gaius) 251-253
Emperor Gaius Aurelius Valerius Diocletianus 284-305
Emperor Gaius Galerius Valerius Maximianus 305-311
Emperor Gaius Valerius Galerius Maximinus 311-313
Saints:
4 saints
Saint Gaius of Ephesus ?-0xx
Saint Caius (a.k.a. Gaius) ?-296
Saint Gaius Francis ?-1597
Saint Gaius of Korea ?-1627
Shakespearian Characters:
7 characters
Julius Caesar (a.k.a. Gaius) Julius Caesar
Cassius (a.k.a. Gaius) Julius Caesar
Gaius Maecenas Antony and Cleopatra
Marullus (a.k.a. Gaius) Julius Caesar
Cinna (a.k.a. Gaius) Julius Caesar
Trebonius (a.k.a. Gaius) Julius Caesar
Gallus (a.k.a. Gaius) Antony and Cleopatra