Upper ocean currents in the Celebes Sea, the northern Maluku Sea, and the adjacent region to the east were measured during February 1999 using a shipboard acoustic Doppler current profiler (ADCP) on R/V Kaiyo. The new data provide the first quasisynoptic observations of the circulation within the central Celebes Sea. South of Mindanao, the Mindanao Current split into three branches. Only the westernmost branch entered the Celebes Sea, where part retroflected around a cyclonic eddy in the western Celebes Sea and part took a shorter route through the eastern basin before the two paths joined and returned to the Pacific. The remainder of the Celebes Sea branch of the Mindanao Current continued toward Makassar Strait. In the central and eastern Celebes Sea, the circulation pattern below 150 m differed substantially from that at the surface. The strongest feature was a northward flow that exceeded 60 cm s-1 near 230 m in the center of the basin, where shallower currents were weak. A northward transport of 6 Sv in the top 300 m was measured across 1.75 ¿N in the Maluku Sea, carrying Indonesian Seas waters northeast toward the Pacific. Water properties and other current sections in the northern Maluku Sea confirm shallow northeastward flow. ¿ 2001 American Geophysical Union