The paper presents the analytical model of a linear two-layer composite beam with partially debonded interlayer contact. The interlayer contact may be also locally fully debonded. The two-dimensional model is materially and geometrically linear, and the governing equations are based on Reissner beam theory. In the partially debonded interlayer contact, only axial slips are allowed. The finger joints are modelled as linear springs. The analytical solution is presented. The kinematic and equilibrium variables are evaluated along the simply supported beam. A parametric study was carried out to analyse the effect of the strength of finger joints and interlayer contact. In addition, different lengths and positions of the fully debonded area of the interlayer contact were analysed, and their effects on selected kinematic and equilibrium variables were observed and commented on. It was shown that the presence of the fully debonded interlayer contact and finger joints significantly affects the behaviour of the beam as well as the stiffness properties of the interlayer contact and finger joints.