Purpose: Assessment is a crucial skill for speech-language pathologists, who rely on standardized tests to identify characteristics of speech, language, hearing, literacy, and related skill sets. Training in assessment administration is an integral part of graduate education that lays the foundation for appropriate use of these tools. Teaching students to administer standardized assessments is time intensive, can vary depending on student learning pace, and involves both general and test-specific knowledge. The current pilot study investigated the effectiveness of researcher-developed and scalable online training modules for beginning and advanced graduate students for knowledge and self-efficacy outcomes. Method: Graduate students (n = 61) across four cohorts (two beginning and two advanced) were trained using online, asynchronous assessment training modules. The modules addressed the administration of standardized assessments using written tutorials, video demonstrations, and quizzes. Students completed pre- and posttests on knowledge and self-efficacy for administering and scoring the trained assessments before and after the online training modules. Results: We found significant pretest to posttest gains in specific assessment-related knowledge for beginning and advanced groups. Following completion of the training modules, beginning graduate students demonstrated increased self-efficacy for general assessment principles, whereas advanced graduate students started and remained high in self-efficacy at posttest. Conclusions: Using researcher-developed online training modules, both beginning and advanced graduate students improved knowledge for assessment skills. These training modules can be used as a model for developing teaching materials across a range of assessments and related topics that are scalable in the context of remote teaching and learning.