Louis Henri Vaquez (August 27, 1860 - 1936) was a French physician who practiced medicine in Paris.
In 1890 he earned his medical doctorate, and in 1898 became professeur agrégé. In 1918 he was appointed professor of clinical medicine and elected a member of the Academy of Medicine. Cardiologist Pierre Potain (1825-1901) was an important influence in his medical career.
Vaquez is remembered for his work in the field of hematology and his research of heart disease. In 1892 he was the first to describe the blood disorder polycythaemia vera or polycythaemia rubra vera , which is also known as "Osler-Vaquez disease" (named with William Osler (1849-1919). He was among the first physicians to recognize the correlation of Stokes-Adams attack to interference of the bundle of His causing a discordant beating of the atria in relation to that of the ventricles. He also performed research involving cardiac arrhythmia and high blood pressure.
Vaquez was founder and editor of the journal Archives des maladies du coeur, vaissaux et du sang.