We investigate the upper mantle seismic discontinuities at 410 and 660 km depth beneath the Indian Ocean Geoid Low (IOGL). To map the discontinuities' topography, we use differential travel times of PP and SS waves and their precursors. Our final data set consists of 37 events with Mw ≥ 5.8, which densely cover our investigation area, also with crossing ray paths. We use array methods to detect the low‐amplitude precursor signals. The best quality data show a deepened 410 km discontinuity in the center of the IOGL as well as a mostly elevated 660 km discontinuity beneath the northern Indian Ocean, which we interpret as a hot anomaly currently residing in the mantle transition zone. We conclude that the largest negative geoid anomaly might be caused by a combined effect of hot material in the midmantle below the innermost IOGL and cold material below 660 km farther south. Key Points PP and SS precursors are used to investigate the topography of mantle transition zone discontinuities beneath the Indian Ocean Geoid Low A hot midmantle anomaly is found beneath the center of the geoid low and a cold anomaly below the transition zone farther south Superposition of the effects of a hot midmantle anomaly and a cold lower mantle anomaly cause the large Indian Ocean Geoid Low