Brosnahan () is an Irish surname. This surname is derived from the place of Brosna, County Kerry, in Ireland. Notable people with the surname include:
James D. Brosnahan (born 1963), American politician Maureen Brosnahan, Canadian journalist Rachel Brosnahan (born 1990), American actress Seán Brosnahan (1911–1987), Irish independent politician
See also Brosnan, another Irish surname of the same derivation Brosnahan Island, an island of the Ross Dependency, Antarctica Kate Spade (born Katherine Noel Brosnahan)