The Thessaloniki Documentary Festival (TDF) is an international documentary festival held every March in Thessaloniki, Greece. TDF, founded in 1999, features competition sections and ranks among the world's leading documentary festivals. Since 2018, TDF is one of the 28 festivals included in the American Academy of Motion Picture, Arts and Sciences Documentary Feature Qualifying Festival List. TDF is organized by the Thessaloniki Film Festival cultural institution, which further organizes the annual Thessaloniki International Film Festival, held every November. French producer Elise Jalladeu is TDF's general director; film critic Orestes Andreadakis serves as its director.

The Thessaloniki Documentary Festival focuses on independent documentary film and emerging documentarists from around the world. TDF is one of the leading documentary festivals globally, with an audience measuring up to 85.000 yearly. TDF is held at the historical “Olympion” theater at the central Thessaloniki Aristotelous Square, at four theaters housed at two restored warehouses at the Thessaloniki Port, and at cinemas across Thessaloniki. The festival hub is Warehouse C, located at the city port.

The Thessaloniki Documentary Festival was founded in 1999, an initiative of Dimitri Eipides, who served as TDF's director until 2016. TDF's initial edition was organized with the contribution of an honorary international committee, consisting of prominent film auteurs as Chantal Ackerman, Judith Elek, Marceline Loridan-Ivens, Johan van der Keuken, Robert Kramer, Alexandr Sokurov, Frederick Wiseman, D.A. Pennebaker and others.

Since its 19th edition in 2017, TDF features competition sections, while from 2018 on, TDF hosts a Virtual Reality films competition section. In 2018 TDF became one of the 28 festivals included in the American Academy of Motion Picture, Arts and Sciences Documentary Feature Qualifying Festival List; the film that wins TDF's “Golden Alexander” award for the Best Documentary in the International Competition section is automatically eligible to submit for Oscar consideration (Documentary Feature category).

In 2020, TDF's 22nd edition was held online from May 19th to May 28th, for the first time in the festival's history, due to the global coronavirus pandemic.