According to the APA Manual (2010), "Because they do not provide recoverable data, personal communications [such as a personal interview] are not included in the reference list. Cite personal communications in text only" (p. 179).
*If you do publish your interview somewhere, such as on a blog or personal website, you would need to include it in the reference list and follow the reference format that fits whatever source you published it to (e.g. if you posted it to a blog, cite it as a blog post).
If you want to cite an interview conducted by someone else that you read online or in a magazine, simply follow the reference format appropriate for that source (e.g. if you read it in a magazine, cite it as a magazine article).