Union of Lebanese Democratic Youth (ULDY) (Arabic: اتحاد الشباب الديمقراطي اللبناني, transliterated: Ittihad ash-Shabab ad-Dimuqrati al-Lubnani), also known as UJDL (the French abbreviation of Union de la jeunesse démocratique libanaise), is a Lebanese leftist secular democratic youth organization as it defines itself in its documents.

Many prominent leftist leaders and activists in Lebanon were affiliated to ULDY during their early political life including Anwar Yassin and Souha Bechara, two former resistors and detainees in Israel, Saadallah Mazraani the Vice General-Secretary of the Lebanese Communist Party and Hanna Gharib the former President of Union of High School Teachers in Lebanon.

This two-year experience set the ground for the 6th National Congress that brought real life to ULDY.

ULDY had its 6th National Congress in May, 2005 and elected Imad Bawab as President and Arabi Andari as General Secretary.

[1] It brought all the constituents of the organization to action and put it back on the political map in Lebanon especially after the big activities and new leadership spirit that it had.