Since its debut over a century ago, forensic psychology has matured into a formally recognized specialty area of psychology with its own set of ethical guidelines; however, a consensual definition of forensic psychology remains elusive. After describing the field’s historical and current struggles to define itself, two ethical issues are discussed that are especially applicable to psychology in legal contexts. The first is the critical differences between serving in therapeutic versus forensic roles and the associated ethical obligation to refrain from serving in both roles in the same case. Despite the terminology used in the literature, treatment in forensic contexts can be ethically appropriate. This chapter considers the current state of the literature regarding treatment in forensic contexts and suggests that this is likely to be an area of future growth for the field. The second ethical issue discussed in this chapter is the insidious effect of the adversarial process on psychologists’ objectivity in forensic contexts, termed “forensic identification” or “adversarial allegiance.” The forensic ethical guidelines affirm the primacy of this issue in forensic contexts, as evidenced by addressing it in the first two published guidelines. However, field and experimental evidence suggest psychologists have a challenging (if not impossible) task in avoiding partiality in adversarial forensic contexts. The chapter ends by briefly considering the methods psychologist might use in an effort to reduce partiality and by recognizing more research is needed to identify what else psychologists can do to strive to uphold the ethical guidelines in this regard.