A sterile connector assembly for mounting on a fluid system includes a first connector and a second connector. The first connector includes a stem defining a fluid passage therethrough, a first housing surrounding the stem and defining a first aperture, and a first valve disposed over the first aperture. The second connector includes a second housing configured to matingly engage the first housing. The second housing defines a second aperture and defines a seal structure. The seal structure is configured to engage the stem. The second connector also includes a second valve disposed over the second aperture. The second valve is configured to engage the first valve when the first housing engages the second housing.