A portfolio is a collection of items that document the professional trajectory or performance of a person in a particular field. Although portfolios originally emerged in artistic contexts as a way of documenting an artist’s work with actual samples, their use has extended to multiple fields. In the field of education, portfolio assessments for teachers have been popular since the 2000s. Portfolios are also commonly used to assess students in the classroom. While this entry focuses on portfolio assessment within an education context, the principles and components apply equally to any holistic assessment procedure that includes a collection of products used as evidence of an individual’s performance.