Provided are a rubber composition for tires which provides both adhesion to fiber cords and conductivity even when an inexpensive conductive carbon black is used, and thus achieves a balanced improvement in conductivity, handling stability, fuel economy, elongation at break, adhesion to fiber cords, processability, and tire durability; and a pneumatic tire including the composition. The composition includes, per 100 parts by mass of a rubber component: 1.0-3.5 parts by mass of sulfur with an iron content of 30 ppm or less, calculated as the net sulfur content in the sulfur; and 0.5-15 parts by mass of conductive carbon black having a DBP of 300 ml/100 g or more and an iron content of 60 ppm or more, the composition having a total net sulfur content of 1.0-6.0 parts by mass per 100 parts by mass of the rubber component, and a volume resistivity of 1.0×108 Ω·cm or less.