The inclusion of pharmacists into general practices has expanded in Australia. However, there is a paucity of research examining interprofessional collaboration and team effectiveness after including a pharmacist into the general practice team in primary or community care. This is a protocol for a cross-national comparative mixed-methods study to (i) investigate interprofessional collaboration and team effectiveness within the general practice team after employing pharmacists in general practices in the Australian Capital Territory (ACT) and (ii) to compare interprofessional collaboration and team effectiveness of pharmacists in general practice across Australia with international sites. The first objective will be addressed through a multiphase sequential explanatory mixed-method design, using surveys and semi-structured interviews. The study will recruit general practice pharmacists, general practitioners, and other health professionals from eight general practices in the ACT. Quantitative and qualitative results will be merged during interpretation to provide complementary perspectives of interprofessional collaboration. Secondly, a quantitative descriptive design will compare findings on interprofessional collaboration (professional interactions, relationship initiation, exchange characteristics, and commitment to collaboration) and team effectiveness of general practice pharmacists in Australia with international sites from Canada and the United Kingdom. The results of the study will be used to provide recommendations on how to best implement the role of general practice pharmacists across Australia.