Lida is a city in Grodno Region, western Belarus, located 168 kilometres (104 mi) west of Minsk. It serves as the administrative center of Lida District. As of 2025, it has a population of 103,262.

The name Lida arises from its Lithuanian name Lyda, which derives from lydimas, meaning "slash-and-burn" agricultural method or a plot of land prepared in this way. Names in other languages are spelled as Polish: Lida and Yiddish: לידע.

There are passing mentions of Lida in chronicles from 1180. Until the early 14th century, the settlement at Lida was a wooden fortress in Lithuania proper. In 1323, the Grand Duke of Lithuania Gediminas built a brick fortress there. The generally considered founding year of Lida is 1380. The fortress withstood Crusader attacks from Prussia in 1392 and 1394 but was burned to the ground in 1710. Following the death of Gediminas, when Lithuania was divided into principalities, Lida became the capital of one of them, the seat of Algirdas.

Lida was in the Grand Duchy of Lithuania. After the Union of Krewo (1385), when the Polish–Lithuanian Union was established, and the subsequent Christianization of Lithuania, the Catholic parish was established in the former Lithuanian pagan lands, and a church, whose ruins still exist, was built by King Władysław II Jagiełło, who visited Lida two times, in 1415 and 1422. In the 15th century, the town became a centre of production by craftsmen and trade. Lida was connected with Vilnius, Navahrudak and Minsk. The town had a market square and four streets: Wileńska, Zamkowa, Kamieńska and Krivaya. In 1506, a Sejm was held in Lida, convened by King Aleksander Jagiellon and the Polish-Lithuanian army gathered here before the Battle of Kletsk, in which it defeated the invading Tatars.

In 1588, Lida became the seat of Lida District in Vilnius Voivodeship. Polish King Sigismund III Vasa granted Lida Magdeburg town rights in 1590, which were later confirmed in Warsaw by Kings Władysław IV Vasa in 1640 and Michael Korybut Wiśniowiecki in 1670 and by the Polish Sejm in 1776. They let Lida hold two annual fairs of little import to the local economy. It was a royal city. The population was between 2000 and 5000 people.

The second half of the 17th century was a difficult time for Lida. During the Russo-Polish War the city was destroyed by the Cossacks in 1655 and the Russians in 1659. As a result of the war in 1656 famine occurred and in 1657 an epidemic. To revive Lida, King Michael Korybut Wiśniowiecki exempted the city from taxes with a privilege of 1676. In 1679 it suffered a fire. In 1702, Lida was plundered by the Swedes.

In 1759, a high school was founded in Lida. By 1786, only 514 inhabitants were left in Lida, in 1792, 1243 people lived here. After the Third Partition of Poland in 1795, it was annexed by the Russian Empire as a powiat centre of the Slonim Governorate (1795).

In estate records and royal forest documents from the 16th to 18th centuries, the Lida area is noted for having predominantly Lithuanian place names and Lithuanian surnames of local peasants. At the start of the 19th century, most people in Lida and the nearby villages were still speaking Lithuanian. From the latter half of that century, however, the region gradually shifted toward Belarusian and Polish influences, a change largely driven by churches and schools. Even so, many villages continued to carry Lithuanian names. In 1862, researcher N. Lebedkin recorded that in the Lida district, 62.2% of the inhabitants were Lithuanian Catholics, 18.9% were Lithuanian Orthodox, 22.6% were Belarusians, and 7.2% were Poles.