Longest Rivers by Continent: Africa, Europe, Americas, Asia, Australia

Top 5 rivers per continent by length (main stem + longest tributary where standard):

Africa

1. Nile — 6,650 km (White + Blue Nile)
2. Congo — 4,700 km
3. Niger — 4,167 km
4. Zambezi — 2,574 km
5. Orange — 1,860 km

Europe

1. Volga — 3,530 km (longest in Europe, flows to Caspian)
2. Danube — 2,860 km (flows to Black Sea, 10 countries)
3. Dnieper — 2,201 km
4. Don — 1,870 km
5. Rhine — 1,230 km (or Pechora 1,809 km if including Arctic Russia)

Americas (North + South)

1. Amazon — 6,400 km (or 6,992 km with Apacheta source) — largest by discharge
2. Mississippi–Missouri — 6,275 km (longest in N. America)
3. Paraná — 4,880 km (Río de la Plata system)
4. Mackenzie — 4,241 km (longest in Canada, to Arctic)
5. Yukon — 3,185 km (Alaska/Bering Sea)

Asia

1. Yangtze (Chang Jiang) — 6,300 km (longest in Asia, 3rd world)
2. Yellow (Huang He) — 5,464 km
3. Mekong — 4,350 km (6 countries)
4. Ob — 3,650 km (to Arctic, with Irtysh 5,410 km)
5. Yenisey — 3,487 km (with Angara/Selenge 5,539 km)

Australia (Oceania)

1. Murray–Darling — 3,672 km (Murray 2,508 + Darling 1,472)
2. Cooper Creek — 1,420 km (intermittent, Lake Eyre Basin)
3. Lachlan — 1,410 km (Murray–Darling tributary)
4. Warrego — 1,160 km
5. Murchison — 820 km (WA, to Indian Ocean)

Lengths vary by source definition (especially Amazon/Nile, Ob/Irtysh). These are consensus modern values.