Peer review is the most legitimate form of evaluation in academia, and a pillar of many decisions and processes in education, research, and other areas of life in higher education. Its legitimacy is based on the peer having relevant expertise to make judgements about the evaluand, and on its presumably external and disinterested character. However, in this chapter we identify what we call “peer advocacy”: when peer reviewers take on the role of promoter or advocate for the evaluand, or for any of the stakeholders involved. To explore this phenomenon, we analyse four cases in the context of Swedish higher education, based on documented studies and the authors’ own experiences. The cases are analysed to show how peer advocacy can be attributed not only to the peer reviewers themselves, but also to the evaluation model, conditions, and expectations. With a view to preserving the legitimacy and integrity of peer review, recommendations are made both to those who commission evaluations and to peer reviewers.