Provided are a tire rubber composition capable of producing a pneumatic tire having excellent rigidity and wear resistance and a pneumatic tire using the same. The tire rubber composition includes 100 parts by mass of a diene rubber (A) and from 1 to 50 parts by mass of elastic microparticles (B), wherein the elastic microparticles (B) have a form of microparticles obtained by crosslinking a crosslinkable oligomer or polymer (b1) in water or an organic solvent, or in the diene rubber (A), and have an average particle size of from 0.001 to 100 μm, the JIS A hardness of a cured product obtained by crosslinking the crosslinkable oligomer or polymer (b1) without use of water, the organic solvent or the diene rubber (A) is greater than 45, and the elongation of the cured product is 200% or greater.