This dissertation presents a general account of embellishment in Mozart’s oeuvre. Chapter 1 lays the theoretical groundwork, distinguishing embellishment from the related techniques of variation, diminution, and structural elaboration. It also examines the various epistemological barriers involved in studying centuries-old improvisations, and situates the project within the culture of historical performance. Chapter 2 examines the relationship between Mozart’s compositional process and his piano technique, arguing that studies of his notated works can, if handled judiciously, shed light on his performing practices. Building upon this unification, Chapter 3 focuses the methods by which embellishment gestures can be discerned in Mozart’s notated works. Chapter 4 examines Mozart’s embellishment protocols, from local gestures such as trills and turns, to large-scale pacing, relating these procedures to broader issues including instrumental technique, operatic characterisation, and the compositional process. Chapter 5 compares Mozart’s embellishments with those by his contemporaries (Vogler, Haydn), students (Ployer, Hummel), and successors (Beethoven). Finally, Chapter 6 considers the role of embellishment in Mozart’s musical aesthetic as a whole. It argues that embellishment provides a lens through which to re-evaluate not only Mozart’s works, but the evolution of musical style, the relationship between analysis and performance, and the role of explanation in musical interpretation