English is a global language in today's world and is present in almost all domains of human activity, including education. As a result, classes in English in international schools have been an upward trend. This thesis aims to give an overview of such educational programs, specifically CLIL and IB programs. It also aims to compare the English language learning objectives of CLIL and IB programs, connecting them with specific curricular elements. Moreover, the thesis intends to compare the language learning methods used in CLIL and IB classes and their impact on the English language proficiency of students. Data from various academic articles and case studies show that both programs require their students to have excellent knowledge of the English language. However, CLIL requires its students to reach a level of English that enables communication and understanding in all contexts and situations. On the other hand, IB requires its students to have the native level of proficiency in English, while focusing on the academic aspect of the language. Moreover, the analysis shows that both programs use innovative language learning methods, which are likely to result in positive improvements in students' language skills. Although IB has been underexplored, especially regarding the language proficiency of IB students, this thesis provides valuable insight into the efficiency and success of both IB and CLIL programs in the context of English language learning and teaching.