Black carbon (BC) is a recalcitrant form of organic carbon (OC) produced by landscapefires.BC is an important component of the global carbon cycle because, compared to unburnedbiogenic OC, it is selectively conserved in terrestrial and oceanic pools. Here we show thatthe dissolved BC (DBC) content of dissolved OC (DOC) is twice greater in major (sub)tropical and high-latitude rivers than in major temperate rivers, with further significant dif-ferences between biomes. We estimate that rivers export 18 ± 4 Tg DBC year−1globally andthat, including particulate BCfluxes, total riverine export amounts to 43 ± 15 Tg BC year−1(12 ± 5% of the OCflux). While rivers export ~1% of the OC sequestered by terrestrialvegetation, our estimates suggest that 34 ± 26% of the BC produced by landscapefires hasan oceanic fate. Biogeochemical models require modification to account for the uniquedynamics of BC and to predict the response of recalcitrant OC export to changing environ-mental conditions.