Swiss novelist, poet, and literary historian whose most lasting achievements are his biographies of Swiss writers and his Swiss-German dialect poetry.

As a biographer Frey showed a predilection for rich character studies in the manner of the 19th-century realists. Because he knew many writers and painters when he was a professor of German literature at Zürich (1898–1920), his portraits of them contain important personal material. Among these biographies are Erinnerungen an G. Keller (1892), C.F. Meyer (1899), A. Böcklin (1903), and Der Tiermaler R. Koller (1906). With his poetry, notably Duss und underm Rafe (1891), rooted in the style of the folk song, he helped inaugurate creative and stylistic developments in Swiss poetry. His historical novels, such as Die Jungfer von Wattenwil (1912; “The Maiden of Wattenwil”), and his plays are considered to be of less importance.