This chapter focuses on the optimization of truss structures, which are widely used in bridges, towers, and industrial buildings. Approaches based on sizing, shape, and topology optimization are presented, showing how truss configuration influences structural performance. The chapter reviews analytical and numerical methods, including heuristic algorithms, that address the complexity of truss optimization. Practical applications demonstrate how optimization supports innovative and efficient designs, balancing safety, economy, and constructability. Emphasis is placed on the versatility of truss systems as benchmarks for testing new optimization strategies. By exploring this structural typology, the chapter provides valuable insights into the interplay between mathematical modeling and practical engineering, illustrating how optimization drives both academic advances and real-world design improvements.