According to AAMC (the MCAT test maker), there are 1 MCAT test centers in Singapore. Most testing centers are located inside a college or university. You can select a testing location that is nearest to you. Please note that you are able to choose a test center when registering for the MCAT.
COMAT TRAINING SERVICE, PROMETRIC TEST CENTER
10 ANSON ROAD, #06-19/20, INTERNATIONAL PLAZA
SINGAPORE, Singapore 079903