DéFI (French pronunciation: [defi] ⓘ; a backronym of Démocrate fédéraliste indépendant [demɔkʁat fedeʁalist ɛ̃depɑ̃dɑ̃]) is a social-liberal[5][3][4] and regionalist[1][2][3] political party in Belgium mainly known for defending French-speakers' interests in and near the Brussels region.

From 1977 until 1980, the FDF participated in the federal governments led by Leo Tindemans and subsequently Wilfried Martens.

From 1992, the FDF regularly competed in electoral alliance with the larger Liberal Reformist Party (PRL).

In 2002 the PRL, the FDF, the MCC and the PFF formed the Reformist Movement (MR), a closer alliance of Francophone liberal parties.

[11] In September 2011, the FDF decided to leave the alliance over disagreements with MR president Charles Michel on the agreement concerning the splitting of the Brussels-Halle-Vilvoorde district during the 2010–2011 Belgian government formation.