Leina is a district of the rural municipality of Georgenthal in the district of Gotha in Thuringia. The village is located around 7 kilometers southwest of the district town of Gotha on the Boxberg. The river Leina, which gave the village its name, was considered to be a turbid body of water due to the sediment from its source in the Thuringian Forest and especially during floods.

The place name appears as Lin aha was first mentioned in writing in 786, in an entry in the Breviarium Lulli. At this time, a manor owned by the Hersfeld monastery was located in the present settlement area. The pre- and early history of the village is well documented by archaeological finds and ground monuments (burial mounds "Im Berlach" and "Auf dem Boxberg"). Several predecessor settlements were discovered during agricultural and construction work in the area, some of which date back to the Neolithic period. Weapon remains, a Roman coin and pottery prove the presence of people around the time of Christ's birth, when several houses were already standing in what is now the village (also documented by postholes and garbage pits).

After the foundation of the neighboring Reinhardsbrunn monastery, this important monastery quickly gained influence in today's Gotha district, numerous donations and purchase contracts increased the monastery's holdings, and from 1295 the village of Leina also became the property of the monastery. The Wettin dynasty, as secular rulers, were the patrons of the Reinhardsbrunn monastery and assigned the village to the Tenneberg district.

On January 1, 1996, Leina became a district of the municipality of Leinatal, which was merged into the newly founded rural municipality of Georgenthal on December 31, 2019.

Leina's most famous attraction is the racecourse on the Boxberg. The Leina Canal runs past the town. This artificial watercourse, built in the Middle Ages, diverted a large part of the Leina water to Gotha.

The first church in Leina was begun in the 12th century; the current choir was started as a late Gothic building. Further alterations were made around 1500, but the church did not take on its present form until 1739 to 1747. St. Nicholas Church marks the historical center of the village. The priest and poet Wilhelm Hey (1789-1854) was born in the rectory. Today, an association is dedicated to researching his life story.