Louis-Alphonse-Victor, 5th duc de Broglie (30 October 1846–26 August 1906), was a French aristocrat.

Eldest son of the monarchist politician Albert, 4th duc de Broglie, he was born in Rome, where his father had a diplomatic post.

On 26 September 1871, he was married to Pauline de La Forest d'Armaillé (1851–1928) in Paris. With her he had four children who survived to adulthood, including two sons, Maurice and Louis, both of whom were physicists and both of whom would hold the ducal title.

He acceded to the title of duc de Broglie on his father's death in 1901, but died only a few years later, passing the title to his eldest son, Maurice, 6th duc de Broglie.