Rubber composition containing at least 10 parts by mass, in 100 parts by mass of a rubber component, of a polymer component (B) containing a residue of an organic acid (A) added in a production process of the polymer, and containing from 10 to 150 parts by mass of a reinforcing filler (C), and 6 parts by mass or less in total of the residue of an organic acid (A) and an organic acid (D) used on mixing, per 100 parts by mass of the rubber component, thereby providing a rubber composition and a tire produced by using the composition, by defining the total amount of an acidic component with respect to the total mixed rubber, including an organic acid, such as stearic acid, and an organic acid contained in a residue of an emulsifier added in a production process of emulsion-polymerized SBR.