Unlike　many　other　state-of-the-art　transition-metal-catalyzed　allylic　substitutions,　cobalt-catalyzed　allylic　substitution　has　received　much　less　attention　from　synthetic　chemists　for　a　long　time　despite　the　fact　that　cobalt　is　an　earth-abundant,　low-cost　and　thus　much　more　sustainable　option　as　either　a　reagent　or　a　catalyst　in　organic　synthesis.　Recently,　there　has　been　an　upsurge　in　the　use　of　cobalt　catalysis　in　allylic　functionalization　reactions,　including　allylic　substitution,　nucleophilic　allylation,　and　Heck-type　allylic　functionalization,　to　construct　synthetically　significant　building　blocks　featuring　a　double　bond　available　for　diverse　downstream　synthetic　manipulations.　This　review　highlights　the　current　development　of　cobalt　catalysis　in　allylic　functionalization　with　an　in-depth　discussion　of　the　reaction　scope　and　mechanistic　insights.