Glued laminated timber Tudor arches have been in wide use in the United States since the 1930s, but detailed knowledge related to seismic design in modern U.S. building codes is lacking. FEMA P-695 (P-695) is a methodology to determine seismic performance factors for a seismic force resisting system. A limited P-695 study for glued laminated timber arch structures highlighted the lack of lateral load testing; therefore, critical modelling information was not available and assumptions based on available research were used. In this study, full-scale lateral load testing of the glued laminated timber arch is used to fill in gaps in test-based information and assess the following characteristics: damping, deformation behaviour, and failure modes.