Abstract: To provide a catalyst composition having high polymerization activity. To provide a polymer manufacturing method. To provide a polymer manufactured by the polymer manufacturing method. To provide a rubber composition including the polymer. To provide a tire using the rubber composition. A catalyst composition including a compound represented by Structural Formula I below, wherein the compound has an OH group at at least one position of the bipyridyl ring; M is a transition metal, a lanthanoid, scandium, or yttrium; R1 and R2 are a hydrocarbon group having one or more carbon atoms or a halogen atom; and R1 and R2 may be the same or different from each other. A polymer manufacturing method including a step of polymerizing one or more selected from the group consisting of a conjugated diene compound and a compound having an ethylenically unsaturated double bond in the presence of the catalyst composition. A polymer manufactured by the manufacturing method. A rubber composition including the polymer.