This study aims to develop and verify a reliable scale to measure boredom and also to identify the relationship between the latent factors that cause boredom and Korean students’ proficiency levels in studying English as a foreign language. 258 college students from diverse majors participated in this study. The students were given a background questionnaire, the English Language Learning Boredom Questionnaire (ELLBQ), which was created for this study, and finally a general English test. The potential factors underlying the ELLBQ suggest a six-factor solution: English language learning boredom, teacher and peer influence, indifference towards English-speaking countries, English tests and homework, absence of assistance, and lack of interest in academic subjects. This study also proves that there are significant differences in English learning boredom depending on English proficiency levels. Learners in the lower-proficiency group were more prone to be affected by English language learning boredom, English tests and homework, and also an absence of assistance compared to those in the intermediate- and high-level groups. Additionally, learners in the intermediate group had higher scores on the survey than low-level ones in terms of teacher and peer influence. Based on the findings,...