We investigate the intraseasonal (30 – 90 day) variations in satellite-observed tropical total ozone (O3) and their connection to the Madden-Julian Oscillation (MJO). Tropical total O3 intraseasonal variations are large (±10 DU) and comparable to those in annual and interannual time scales. These O3 anomalies are mainly evident in the subtropics over the Pacific and eastern; hemisphere and propagate slowly eastward (5 m s 1). The subtropical negative (positive) O3 anomalies are typically collocated with the subtropical upper troposphere anticyclones (cyclones) generated by equatorial MJO convection and f lank or lie to the west of the equatorial enhanced (suppressed) MJO convection. The subtropical O3 are anticorrelated with geopotential height anomalies near the tropopause and thus mainly associated with the O 3 variability in the stratosphere rather the troposphere. Over the equatorial regions, total O3 anomalies are small.