A job analysis was conducted to define the knowledge important for entry-level physics teachers. The results will be used to guide the development of new test content specifications for the Praxis Series Physics assessment. A draft domain was constructed from the existing test content specifications, national standards, and feedback from item writers, examinees, and standing committees. A national advisory committee (NAC) of 10 teachers and two college faculty reviewed and modified the draft domain to reflect the knowledge they believed was important for safe and effective practice and needed at time of entry into the profession. The revised domain consisted of 54 statements clustered within six major categories: (a) Modern Physics, Atomic and Nuclear Structure; (b) Heat, Energy, and Thermodynamics; (c) Mechanics; (d) Electricity and Magnetism; (e) Optics and Waves; and, (f) Scientific Inquiry, Processes and Social Perspectives. Survey responses of 452 educators provided independent evidence of the importance of the domain. Respondents judged each knowledge statement on a scale ranging from 1 (not at all important) to 5 (extremely important). A total of 52 knowledge statements had mean ratings above 3.50 in the aggregate sample and for subgroups containing more than 30 respondents. The results indicate that these 52 statements may be considered appropriate for guiding the development of new test content specifications for the Praxis Physics assessment.