Introduction. In the 21st century, geography learning must be understood in a broader context as a part of the whole education with contemporary features and is able to fulfill recent and future challenges. Geography teacher candidates are required to be professional and possess the complexity of the competencies that must be mastered. Consequently, teachers must be more competent in providing quality learning to students following the demands of 21st-century learning. This study aimed to find the factors determining the readiness of educational students as 21st-century professional geography teacher candidates. Study participants and methods. The research was carried out using a survey method involving 349 students of geography education from campuses in and outside Java Indonesia. The analysis used was the second-order Confirmatory Factor Analysis (2nd CFA) and Structural Equation Modeling (SEM) analysis technique and continued with descriptive-narrative analysis to describe the achievements of each variable. Results. The results showed that the Student Readiness as Professional Teacher Candidates of the 21st Century (KMSGP) both in Java and outside Java showed a significant value, which means that all factors influence the formation of the KMSGP. The strongest indicator in the formation of KMSGP in Java and outside Java is Educators Creating an Environment That Respects Learner Diversity (X2) with a significant relationship of more than 84%. Meanwhile, other indicators that are also high are that Educators Understand the Materials They Teach Well (X3) with a significant relationship of 90% for campuses in Java and Educators Show Leadership (X1) with a significant relationship of 88% for campuses outside Java. Practical significance. Based on the results, the competence of teacher candidates needs to be improved. The efforts can be carried out through tutoring programs, lesson study, designing an authentic learning environment by utilizing learning technology, improve teaching practices in universities, experimental learning, integrating technology in teacher education, teaching multicultural pedagogic skills, self-development, and self-improvement.