AbstractUltrafast optical switch based on plasmonic nanostructures has large application potentials in optical logic circuits and optical communication systems. Integration of plasmonic optical switching devices with optical fibers is a breakthrough for realizing practical applications in long‐range optical data transmission or communication techniques. Here, the incorporation of plasmonic optical switch devices onto the end facets of optical fibers is reported, so that the switched optical signals are generated by interaction between femtosecond laser pulses and plasmonic nanostructures on one end of the fiber, and are delivered via the fiber waveguide to the other end for detection or decoding. “Quenching” of localized surface plasmon in the gold nanowires by its interaction with band‐edge modulation in gold through strong optical excitation is the responsible photophysics. This work accomplishes for the first time the implementation of ultrafast plasmonic optical switch device on optical fiber tips for logic data transmission.