The objective was to establish consensus-based competencies for oncology within physical therapist professional education programs in the United States. A mixed-methods approach implementing a sequential exploratory design that included 3 phases was used to establish oncology competencies for physical therapist professional education programs. Participants in each phase were physical therapists representing diverse practice settings, experience levels, and geographical regions. Student physical therapists were included in phases 2 and 3. Three online focus groups were followed by an in-person group discussion to establish cancer-related themes, domains of practice, and competencies. Participants evaluated the competencies in a 3-round modified Delphi study for relevance and clarity. Each competency required 80% consensus using a Likert scale (1 = not at all relevant/clear, 5 = extremely relevant/clear). It was not accepted if a competency did not meet the 80% threshold by the end of round 3. Six domains of practice and 28 competencies were developed and evaluated. Within the 6 domains, 21 competencies were accepted: general cancer concepts (n = 4), musculoskeletal system (n = 3), neurologic system (n = 5), integumentary system (n = 2), cardiovascular and pulmonary system (n = 5), and involvement of multiple systems across the lifespan (n = 2). Along with the 21 competencies, participants also recommended 11 overarching oncology themes to incorporate into physical therapist professional education programs. Delivering cancer content using a body systems approach was recommended. As the number of survivors of cancer continues to grow, integration of these essential competencies within physical therapist professional education programs will improve the profession's capacity to provide quality care to meet the societal need of persons living with and beyond cancer. Academic and clinical educators should integrate these competencies to ensure that physical therapist professional education programs appropriately prepare physical therapists for providing care for persons living with and beyond cancer across the lifespan.