Massachusetts Eye and Ear (Mass. Eye and Ear, or MEE) is a specialty hospital located in Boston, Massachusetts, United States, which focuses on ophthalmology (eye), otolaryngology (ear/nose/throat), and related medicine and research. Founded in 1824 as the Boston Eye Infirmary (BEI), it has also been known as the Massachusetts Charitable Eye and Ear Infirmary (MCEEI), and Massachusetts Eye and Ear Infirmary (MEEI). It is a teaching partner of Harvard Medical School.

Massachusetts Eye and Ear has earned an international reputation for its successful treatment of the most difficult diseases and conditions of the eye, ear, nose, throat, head, and neck, and for its outstanding contributions to medical research and education. In 2018, Massachusetts Eye and Ear has two adult specialties nationally ranked the "U.S. News Best Hospitals Rankings and Ratings 2018-18, with the Department of Ophthalmology ranked number four in the U.S. and the Department of Otolaryngology placing number six in the nation.

The primary teaching hospital for Harvard Medical School in ophthalmology and otolaryngology, Massachusetts Eye and Ear trains more than 110 residents and fellows each year in its various sub-specialties, including cornea, neuro-ophthalmology, retina, eye pathology, pediatrics, glaucoma, ocular oncology, immunology, head & neck surgery, oncology, pediatric otolaryngology, facial plastics, otology and oto-neurology. In addition to ophthalmology and otolarynology, the hospital provides patient services and conducts research and clinical training in audiology (diagnostics, hearing aids and cochlear implants), balance (vestibular), facial nerve, thyroid, voice and speech, and vision rehabilitation.