The present invention provides a rubber composition that improves in terms of the fuel economy of a rubber composition containing an isoprene-based rubber and also offers favorable durability and favorable processability or adhesion to steel cords, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for a bead apex, sidewall packing, base tread, or breaker cushion, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of sulfur; and a specific amount of a compound represented by formula (I) below. The present invention also relates to a rubber composition for a steel cord topping, strip adjacent to steel cords, or tie gum, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of an organic acid cobalt salt; and a specific amount of a compound represented by the formula (I).