Intravascular devices, systems, and methods are disclosed. In some embodiments, side-loading electrical connectors for use with intravascular devices are provided. The side-loading electrical connector has at least one electrical contact configured to interface with an electrical connector of the intravascular device. A first connection piece of the side-loading electrical connector is movable relative to a second connection piece between an open position and a closed position, wherein in the open position an elongated opening is formed between the first and second connection pieces to facilitate insertion of the electrical connector between the first and second connection pieces in a direction transverse to a longitudinal axis of the intravascular device and wherein in the closed position the at least one electrical contact is electrically coupled to the at least one electrical connector received between the first and second connection pieces.