Korea declared in 2006 that measles had been eliminated; however, a measles outbreak occurred in the southeastern area of Korea in 2011. Active surveillance of measles patients was conducted in Seoul 3 cases were detected in 2013 and 103 cases in 2014. Of 106 confirmed measles patients, 32 cases were within one university in Seongbukgu, and 23 were within three schools in Yongsangu. Students 14~29 years old comprised 78.3% (83/106) of the cases, and 75.5% (80/106) of the measles viruses were of genotype B3. One foreign traveler played an important role in the measles outbreak in Seoul. This measles outbreak in Seoul may provide useful data for future epidemiological studies of measles.