Liège–Bastogne–Liège, also known as La Doyenne ("The Old Lady"), is a one-day classic cycling race in Belgium. First run in 1892, it is the oldest of the five Monuments of the European professional road cycling calendar; usually coming as the last of the spring classics. It is held annually in late April, in the Ardennes region of Belgium, from Liège to Bastogne and back.

It is considered one of the most arduous one-day cycling events in the world because of its length and demanding course. The most successful rider with five victories is Belgian rider Eddy Merckx, trailed by Italian Moreno Argentin in the 1980s and Spaniard Alejandro Valverde in the 2000s, who both won the race four times.

Liège–Bastogne–Liège is part of the UCI World Tour competition. It is the concluding race of the Ardennes Classics series, which includes La Flèche Wallonne. Both are organised by French owner Amaury Sport Organisation, which also organises the Tour de France and Paris–Roubaix.

In 2017, the Liège–Bastogne–Liège Femmes was inaugurated and added to the UCI Women's World Tour, becoming the second of the cycling monuments to introduce a women's edition after the Tour of Flanders in 2014.