Lionbridge Technologies, Inc. is a company specializing in language localization, software testing, and e-learning.

The company was founded in 1996. In 2005, they acquired Bowne Global Solutions, then the largest localization provider worldwide. They acquired Darwin Zone, a digital marketing services agency based in Costa Rica, and Clay Tablet Technologies, a content connectivity software firm, in 2014.

In 2015, they acquired Zurich-based CLS Communication, a translation solutions provider, and Geotext, a legal translation company. In December 2016, it was announced that Lionbridge entered into a definitive agreement to be acquired by H.I.G. Capital. The deal was announced closed in May, 2017.

A securities class action lawsuit involving the company was filed in July 2001 under "Samet v. Lionbridge Technologies, Inc. et al." in the United States District Court for the Southern District of New York.

In 2006, a Lionbridge employee was awarded noneconomic damages of USD 366,250 and economic damages of USD 221,433 due to failure by the company to fulfil its obligation to help the employee obtain a green card.

A 2008 court case involved an unfair dismissal claim by a former Lionbridge employee fired for union recruitment activities at the company's Warsaw office to protect employment conditions. Protests in support were held in Denmark, Spain, Poland, and Ireland.

Every year since 2006, Lionbridge has been named a Top 20 Training Outsourcing Company.