A very light (GeV scale) dark gauge boson ($Z$) is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the $3.6 sigma$ deviation in the muon $g$-2 measurement. We suggest top quark decays as a venue to search for light dark force carriers at the LHC. Such $Z$s can be easily boosted, and they can decay into highly collimated leptons (lepton-jet) with large branching ratio. We investigate a scenario where a top quark decays to $b W$ accompanied by one or multiple dark force carriers and find that such a scenario could be easily probed at the early stage of LHC Run 2.
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