In this chapter, we focus on the consideration of thin-walled beams whose walls are made of composite laminates and, in addition to bending with normal force, we also consider the topics of transverse shear force and torsion. The treatment of the elementary load-bearing behaviour of thin-walled composite beams is a very lively field of work and research, for which a large number of research papers are available. Interested readers can gain an overview of this field of knowledge with the review paper by Mittelstedt (2020).