Yes, most UK schools want proof that you speak English well, and IELTS is the most common way to prove it. Some schools take TOEFL, PTE Academic, or Cambridge English. You usually need a score between 6.0 and 7.5 on IELTS, but it depends on the course. You might not need IELTS if you studied in English before or went to a school the UKVI recognizes. Always check what your university wants.