The role of a compiler in programming is to translate high-level source code written in languages like C or Java into low-level machine code that can be executed by a computer's CPU. Compilers analyze the code for syntax errors, optimize it for performance, and generate executable files. This process allows developers to write code in a more understandable and manageable form while ensuring that the computer can execute it efficiently. Compilers play a crucial role in the development process, enabling the transition from programming to actual executable applications.