Building upon evidence supporting the co‐occurrence of behavioural addictions, this study delved into the relationship between social media doomscrolling and celebrity worship among university student social media users in Iran and the United States. Objectives were threefold: (a) provide psychometric support for the Social Media Doomscrolling Scale (SMDS), (b) examine psychological correlates of doomscrolling and celebrity worship, and (c) explore the relationship between doomscrolling and celebrity worship. The SMDS demonstrated good psychometric properties in the US sample, like the original study of the SMDS conducted in an Iranian sample. Doomscrolling showed a positive association with future anxiety and a negative association with psychological well‐being in both US and Iranian samples. Celebrity worship was positively linked with future anxiety in the Iranian and US samples. A positive correlation emerged between doomscrolling and celebrity worship in both the US and Iranian samples. This cross‐cultural study offers preliminary evidence for the co‐occurrence of two emerging media‐related behavioural addictions.