Authorial identity is the sense a writer has of themselves as an author and the textual identity they construct in their writing. This article describes two studies exploring psychology students' authorial identity in academic writing. A qualitative focus group study with 19 students showed that authorial identity was largely unfamiliar to students, and highlighted the obstacles perceived by students to constructing authorial identities in university assignments. A questionnaire survey of 318 students explored the factor structure of an 18‐item Student Authorship Questionnaire. Three factors described aspects of student authorial identity (‘confidence in writing’, ‘understanding authorship’ and ‘knowledge to avoid plagiarism’), and three factors described approaches to writing (‘top‐down’, ‘bottom‐up’ and ‘pragmatic’). Confidence in writing and knowledge to avoid plagiarism were significantly higher among year 2 than year 1 students. Both studies could inform interventions to reduce unintentional plagiarism by improving students' authorial identity.