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. (Contains 3 tables and 1 figure.)