The gas-phase reaction of Cl atoms with benzene has been studied using both experimental and computational methods. The bulk of the kinetic data were obtained using steady-state photolysis of mixtures containing Cl₂, C₆H₆, and a reference compound in 120-700 Torr of N₂ diluent at 296 K. Reaction of Cl atoms with C₆H₆ proceeds via two pathways; (a) H-atom abstraction and (b) adduct formation. At 296 K the rate constant for the abstraction channel is k_1a = (1.3 ± 1.0) × 10^-16 cm³ molecule^-1 s^-1. Phenyl radicals produced via H-atom abstraction from C₆H₆ react with Cl₂ to give chlorobenzene. The main fate of the C₆H₆-Cl adduct is decomposition to reform C₆H₆ and Cl atoms. A small fraction of the C₆H₆-Cl adduct undergoes reaction with Cl atoms via a mechanism which does not lead to the production of C₆H₅Cl, or the reformation of C₆H₆. As the steady-state Cl atom concentration is increased, the fraction of the C₆H₆-Cl adduct undergoing reaction with Cl atoms increases causing an increase in the effective rate constant for benzene removal and a decrease in the chlorobenzene yield. Thermodynamic calculations show that a rapid equilibrium is established between Cl atoms, C₆H₆, and the C₆H₆-Cl adduct, and it is estimated that at 296 K the equilibrium constant is K_c,1b = [C₆H₆-Cl]/[C₆H₆][Cl] and lies in the range (1-2) × 10^-18 cm³ molecule.¹ Flash photolysis experiments conducted using C₆H₆/Cl₂ mixtures in 760 Torr of either N₂ or O₂ diluent at 296 K did not reveal any significant transient UV absorption; this is entirely consistent with results from the steady-state experiments and the thermodynamic calculations. The C₆H₆-Cl adduct reacts slowly (if at all) with O₂ and an upper limit of k(C₆H₆-Cl + O₂) < 8 × 10^-17 cm³ molecule^-1 s^-1 was established. As part of this work a value of k(Cl + CF₂ClH) = (1.7 ± 0.1) × 10^-15 cm³ molecule^-1 s^-1 was measured. These results are discussed with respect to the available literature concerning the reaction of Cl atoms with benzene.