Provided are an apparatus and method for measuring bio-information. The apparatus for measuring bio-information includes: a pulse wave sensor configured to emit light of multiple wavelengths onto an object, and detect the light to obtain multi-wavelength pulse wave signals when the light is reflected or scattered from the object； and a processor configured to: obtain a conversion signal that indicates a contact pressure between the object and the pulse wave sensor, based on the multi-wavelength pulse wave signals, obtain an oscillometric envelope based on the multi-wavelength pulse wave signals and the conversion signal, and obtain bio-information based on the oscillometric envelope.
