Yes, IELTS is a mandatory component for Express Entry if you choose to prove your English proficiency. Specifically, you must take the IELTS General Training test, as Academic IELTS is not accepted. Alternatively, CELPIP-General is also accepted for English, while French-speaking applicants may submit TEF or TCF results. Language test scores directly contribute to your CRS score and overall eligibility points. Higher scores in speaking, reading, writing, and listening can significantly improve your chances of receiving an Invitation to Apply. Therefore, preparing well for the language test is a critical step in the Express Entry process.