Enguerrand IV, Lord of Coucy (c. 1236 – 1311) was the son of Enguerrand III, Lord of Coucy and Marie de Montmirail [fr].

Enguerrand IV's rule was notable for his crimes and cruelty.

Setting an important medieval legal precedent, King Louis IX of France refused to allow him trial by combat for the hanging of three Flemish squires found on his land, and imprisoned him instead in 1259 in the Louvre.

[2] In the end, Enguerrand escaped with a fine,[3] and through his wealth remained important to the King, lending him 15,000 livres in 1265 to purchase a piece of the True Cross.

[5] He had no children by either marriage and was succeeded in 1311 by the second son of his sister, Alix, who became Enguerrand V.