The purpose of the present study was to evaluate the factorial structure of the bullying scale on the Trends in International Mathematics and Science (TIMSS 2019) for eighth graders and evaluate the instrument’s invariance across gender so that tests of level between males and females can be conducted. Data came from the 2019 cohort of TIMSS in Saudi Arabia. The 14-item scale was evaluated using three competing models: (a) a unidimensional structure, (b) the International Association for the Evaluation of Educational Achievement (IEA) online, non-online two-factor model, and (c) the Wang et al. (2012) 4-domain bullying taxonomy. Participants were 5567 eighth graders who participated in the 2019 TIMSS study. There were 2856 females and 2711 males. The mean age was 13.9 years. Data were analyzed using Confirmatory Factor Analysis (CFA) and Mplus 8.9. Results indicated that a 4-domain structure including verbal, physical, relational, and online bullying represented the most optimal factor structure of the 14-item bullying measure. Tests of exact measurement invariance for gender originally failed but were then satisfied using the newly recommended “alignment” methodology. Latent mean differences were salient and significant suggesting that levels of bullying across all domains were elevated in males compared to females, contrasting earlier views that different types of bullying are linked to males versus females. Results are discussed in relation to educational policy interventions.