Qualitative interviews are widely used in qualitative and mixed methods research designs in applied linguistics, including case studies, ethnographies, interview studies, and narrative research. This entry discusses commonly used forms of interviews and provides examples to show how researchers use interview accounts to generate knowledge about topics in applied linguistics. Steps in the design of qualitative studies using interviews include formulating research questions that can be examined using interviews, considering sampling and selection criteria, developing an interview guide, submitting proposals for ethical review, and recruiting participants. Examples of interview questions and innovations in interview methods are discussed, including dialogic forms of interviews, online interviewing, approaches to elicitation, and mobile methods. Theorizations of interviews discussed in applied linguistics are reviewed along with issues related to the transcription, translation, and analysis of interview data. The entry concludes by discussing the assessment of quality and the future of interview research.