This paper presents a comprehensive overview of classical and quantum cryptanalysis methods targeting block ciphers. We examine traditional attack strategies such as brute-force search, differential and linear cryptanalysis, as well as advanced algebraic and statistical methods. We also investigate how quantum computing alters the security landscape by enabling attacks like Grover-based key search and quantum differential cryptanalysis. The paper highlights both theoretical foundations and practical implications, providing insight into post-quantum secure block cipher design.