Alexandre Jean Albert Lavignac (21 January 1846 – 28 May 1916) was a French music scholar, known for his essays on theory, and a minor composer.

Among his pupils were Henri Casadesus, Claude Debussy, Vincent d'Indy, Amédée Gastoué, Philipp Jarnach, Henri O'Kelly, Gabriel Pierné, Wadia Sabra, Florent Schmitt.

In March 1864, at the age of eighteen, he conducted from the harmonium the private premiere of Gioachino Rossini's Petite messe solennelle.

His condensed work, La Musique et les Musiciens, an overview of musical grammar and materials, continued to be reprinted years after his death.

Lavignac edited the compendious Encyclopédie de la Musique.