Online education grows at a level far beyond that of overall higher education; millions of students are taking online courses. Online assignments often elicit unpleasant emotional responses (e.g., frustration). However, the issue of regulating students' emotion to complete online homework has been notably missing from much online learning literature. The aim of our investigation is to validate the Online Homework Emotion Regulation Scale (OHERS), based on data from 612 undergraduates. The sample was randomly split into two groups, where each group was used for exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), respectively. Both EFA and CFA findings indicated that the OHERS consisted of two subscales: Emotion Management and Cognitive Reappraisal. In addition, the OHERS and its subscales showed very good to excellent reliability. Regarding the validity evidence of the OHERS, emotion management and cognitive reappraisal were positively associated with online homework purposes, behaviors, learning strategies, and e-learning satisfaction, consistent with theoretical expectations.