Inner liner rubber composition for a pneumatic tire, which enables improvements in handling stability, fuel economy, elongation at break, sheet processability, air barrier properties, and compounding cost in a balanced manner. Also, pneumatic tire including inner liner formed from the rubber composition. The rubber composition includes: reclaimed butyl rubber; halogenated butyl rubber other than the reclaimed butyl rubber; at least one semi-reinforcing filler selected from finely ground bituminous coal having a specified average particle size, talc, mica, and hard clay; and carbon black having a specific N2SA and/or silica having a specific N2SA. The rubber composition has a predetermined reclaimed butyl rubber content, a predetermined combined content of the reclaimed butyl rubber and the halogenated butyl rubber, a predetermined total semi-reinforcing filler content, and a predetermined combined content of the carbon black and the silica.