The Democratic United National Front (DUNF; Sinhala: ප්‍රජාතන්ත්‍රවාදී එක්සත් ජාතික පෙරමුණ, romanized: Prajathanthrvadi Eksath Jathika Peramuna, Tamil: ஜனநாயக ஐக்கிய தேசிய முன்னணி) is a political party in Sri Lanka. It was founded in the early 1990s by a group of United National Party dissidents who were critical of then-incumbent president Ranasinghe Premadasa. The party was led by Lalith Athulathmudali, Gamini Dissanayake who shared a joint presidency and G. M. Premachandra.

On 23 April 1993, Lalith Athulathmudali was assassinated during an election campaign rally. The DUNF underwent a major split and Athulathmudali's widow, Srimani Athulathmudali, launched the Democratic United National Lalith Front as a separate political party. This party would later be renamed as the New Democratic Front.

At the 2004 Sri Lankan parliamentary elections, the party was part of the SLFP-led United People's Freedom Alliance, which won 45.6% of the popular vote and 105 out of 225 seats.

In December 2009, the DUNF joined the UNP-led United National Front. However, in February 2010 they left the UNF to join the Democratic National Alliance led by Sarath Fonseka.