The study of the aggregation of soluble proteins into highly ordered, insoluble amyloid fibrils is fundamental for the understanding of neurodegenerative disorders. Here, we present a method for the observation of single amyloid fibrils that allows the investigation of fibril growth, secondary nucleation or fibril breakup that is typically hidden in the average ensemble. Our approach of thermophoretic trapping and rotational diffusion measurements is demonstrated for single Aβ40, Aβ42 and pyroglutamyl-modified amyloid-β variant (pGlu3-Aβ3-40) amyloid fibrils.