simple_rl is a minimalistic Python library designed to streamline reinforcement learning research and education. It provides a consistent API for defining environments and agents, with built-in support for common RL paradigms including Q-learning, Monte Carlo methods, and dynamic programming algorithms like value and policy iteration. The framework includes sample environments such as GridWorld, MountainCar, and Multi-Armed Bandits, facilitating hands-on experimentation. Users can extend base classes to implement custom environments or agents, while utility functions handle logging, performance tracking, and policy evaluation. simple_rl's lightweight architecture and clear codebase make it ideal for rapid prototyping, teaching RL fundamentals, and benchmarking new algorithms in a reproducible, easy-to-understand environment.