Tropical forests continue to undergo a rapid transformation. The expansion of rubber tree (Hevea brasiliensis) plantations has been reported as a major driver of forest loss, linked to a boom in market demand. Distant commodity markets have spurred a surge of large-scale economic land concessions granted throughout tropical Southeast Asia. Using satellite imagery, we show the impact of rubber tree plantations on Cambodian forest cover and analyse how annual forest-to-rubber conversion rates relate to global rubber prices from 2001 to 2015. We found that 23.5 ± 1.8% of national forest cover was cleared in this period, with 23.2 ± 3.6% of cleared forest converted to rubber plantations. Annual forest-to-rubber conversion rates closely correlated with global rubber prices, with a time lag of 8-9 months (Pearson's r = 0.93). Our results reveal a strong link between global commodity markets and tropical forest loss, particularly in countries with land policies geared towards rapid development.