Lielupe (Latvian - Lielupe, translated "Big river"; German and old Russian name - Курляндская Аа, German - Kurländische Aa) is a river in Latvia. Length is 119 km, basin area - 17,6 thousand km². Falls into the Gulf of Riga (one fork into Daugava River). On the Lielupe are cities Jelgava and Kalnciems, in lower reaches, between the left shore and the coast of Riga, - city Jūrmala, on the right shore - a city, which is part of the Jūrmala, Priedaine. It (Lielupe) is navigable for Jelgava. In Soviet time on the line Riga-Jūrmala were exploited hydrofoils, like "Raketa".
Lielupe - meaningfully second river in Latvia. It is formed by merger of rivers Nemunėlis and Mūša, near Bauska. Liepule is shorter than Nemunėlis (191 km) and Mūša (164 km). Lielupe has more than 250 inflows (Buļļupe, Iecava, Svete and others). On Lielupa there are better circumstances for shipping, than on the other Latvian rivers.