The Clinical Nurse Leader (CNL) is a master's prepared nurse envisioned to provide clinical leadership at the microsystem level to ensure safe, high quality patient-centered care. The American Association of Colleges of Nurses defined ten 'fundamental aspects' of CNL practice, but as the certified CNL population grows, data suggest they are filling a variety of positions besides formally designated CNL roles. This article reports the results of a systematic review of CNL literature to better understand what roles and activities certified CNLs are enacting when not hired into formally designated CNL roles. Sixty-nine articles met inclusion criteria. Roles identified include: faculty, 62%; clinical management/executive, 12%; specialty clinician, 11%; and staff nurse, 9%. In these roles, certified CNLs are reviewing literature, conducting research, and/or writing commentaries on CNL education and practice and other health foci such as alarm fatigue, insulin practices, and physical exercise for cancer-related fatigue. Results indicate that despite a lack of formal tracking of certified CNLs over time, the available information identifies a variety of roles and job titles used by this group of professional nurses. The study findings add to the body of knowledge informing overall understanding of the CNL initiative.