Oxygen-iodine lasers that utilize electrical or microwave discharges to produce singlet oxygen are currently being developed. The discharge generators differ from conventional chemical singlet oxygen generators in that they produce significant amounts of atomic oxygen. Post-discharge chemistry includes channels that lead to the formation of ozone. Consequently, removal of I(P-2(1/2)) by O(P-3) atoms and O-3 may impact the efficiency of discharge driven iodine lasers. In the present study, we have measured the rate constants for quenching of I( P-2(1/2) ) by O(P-3) atoms and O-3 using pulsed laser photolysis techniques. The rate constant for quenching by O-3, (1.8 +/- 0.4) x 10(-12) cm(3) s(-1), was found to be a factor of 5 smaller than the literature value. The rate constant for quenching by O(P-3) was (1.2 +/- 0.2) x 10(-11) cm(3) s(-1).