The present invention provides a rubber composition capable of producing a rubber molded article that is excellent in rolling resistance performance, steering stability, mechanical strength and abrasion resistance, and a tire obtained by using the rubber composition in at least a part thereof. The present invention relates to a rubber composition including (A) a rubber component including at least one rubber selected from the group consisting of a synthetic rubber and a natural rubber, (B) silica and (C) a modified polymer of farnesene obtained by introducing a functional group into a polymer of farnesene, in which a content of the silica (B) in the rubber composition is from 20 to 150 parts by mass on the basis of 100 parts by mass of the rubber component (A), and a content of the modified farnesene polymer (C) in the rubber composition is from 2 to 10 parts by mass on the basis of 100 parts by mass of the silica (B).