In Canada, "I Think I'm in Love with You" reached the top twenty, peaking at number fourteen. It became her second top twenty in that country. The song also reached number two on the Canada "RPM" singles chart and was her highest peak at the time. The song stayed on the chart for twenty weeks. In Australia, the single debuted at number thirty on the ARIA Charts during the week of June 25, 2000. Five weeks later, it reached number ten and was her second top ten there. The single stayed on the chart for fifteen weeks. It was later certified gold by the Australian Recording Industry Association (ARIA), denoting shipments of 35,000 units within the country. In New Zealand, the song debuted at number thirty-three on the issue of August 6, 2000. In its third week on the chart, the single peaked at number twenty.