A vehicular interior rearview mirror assembly includes a mirror head having an interior mirror reflective element. The mirror reflective element has a mirror transflector that transmits near-IR light incident thereon, transmits visible light incident thereon and reflects visible light incident thereon. The mirror assembly includes a camera disposed within the mirror head and viewing through the mirror transflector. The camera includes an imaging sensor having a quantum efficiency (QE) of at least 15% for near-infrared (near-IR) light having a wavelength of 940 nm. The mirror assembly further includes first, second and third near-IR illumination sources disposed within the mirror head and operable to emit near-IR light that passes through the mirror transflector. The near-IR illumination sources are at respective angles relative to a planar front surface of the mirror reflective element and, when powered, illuminate respective in-cabin regions for a driver monitoring function or an occupant detection function.