The people who use complementary medicines (CMs) believe that these medicines are safe and harmless. They could easily access CMs like herbal or traditional medicines in community pharmacies. Therefore, community pharmacists are important professionals in advising the safe choices of CMs and providing evidence-based information for customers to decrease adverse effects of CMs. To systematically review knowledge, attitude, and practices of community pharmacists about CMs, and the factors associated with CM practices of dispensing, recommending and counseling patients, and answering the patients' queries. An electronic search was performed with four databases: PubMed, Scopus, SpringerLink and ScienceDirect, from 1990 to 19th May 2022. The inclusion criteria were studies 1) about knowledge, attitude, and/or practices of community pharmacists about CMs, 2) written in English, 3) conducted with quantitative methods, and 4) able to retrieve full text. Twenty-three studies were included in this systematic review. Some studies showed that less than half of the pharmacists asked or counselled about CMs to their patients and answered the patients' queries about CMs. Only 20% of the pharmacists did report CM side-effects. Training or education about CMs was a common factor associated with the CM practice of dispensing, recommending, counseling, and answering the patients' queries about CMs. CMs recommended most by community pharmacists were vitamins & minerals, food or dietary supplements, fish oil and probiotics. The most common dispensed CMs were vitamins & minerals, herbs, food or dietary supplements, fish oil and essential oils. Lacks of reliable information sources and scientific evidence were common barriers for the CM practices. Being less expensive than conventional medicines motivated the pharmacists to recommend and discuss about CMs. The community pharmacists that participated in included studies suggested strengthening CM trainings and highlight the pharmacist role in CM therapy. A high percentage of community pharmacists did dispense CMs to their patients, while a low percentage of the pharmacists did report CM side effects. Pharmacists were most comfortable recommending and responding the patients' CM queries. Training or education about CMs associated with CM dispensing, recommending, discussing, and answering the patients' queries about CMs was recommended.