A fitting for a harness, such as a trapeze harness for a sailboat is disclosed. The fitting comprises: a first part secured to or securable to a harness, a second part connectable to a tether, and a mechanism to releasably inter-connect the first and second parts. The mechanism comprises a plurality of locking members each having a rounded or tapered locking part, configured to be received within a respective locking aperture located on the second part. A locking element is provided which is moveable between a locking position and a release position and is configured to urge each locking member into a position in which its locking part is received within a respective locking aperture when the locking element is in the locking position. This enables the first part and the second part to be releasably locked together.