Geoffrey V (French: Geoffroy), nicknamed le Trouillard, was the Lord of Joinville from 1190 until his death in late 1203 or early 1204. He was also the hereditary seneschal of the County of Champagne. He went on both the Third Crusade (1189–90) and the Fourth Crusade (1202–04), where he died.
Geoffrey was the eldest son of Geoffrey IV of Joinville and Héluis (Helvide), a daughter of Guy I of Dampierre. His maternal grandfather had gone on a crusade in 1125. In 1189, Geoffrey accompanied his father on the Third Crusade. He was praised in the Bible of Guyot de Provins: "Who was Geoffrey of Joinville? By Saint Giles, they do not have a better knight than him that side of the Punta del Faro." His prowess was such that King Richard I of England, a leader of the Third Crusade, as a mark of favor gave him the right to marshall his family's arms with those of England. His father died in at the siege of Acre in August 1190.
Geoffrey was present at the wedding of Count Theobald III and Blanche of Navarre in Chartres on 1 July 1199, where he signed Theobald's act granting a dower to Blanche. In the week after Theobald's death (24 May 1201), Geoffrey was at Sens when Blanche rendered homage to King Philip II for Champagne on behalf of the child she was bearing, the future Theobald IV.
Following the death of Theobald, who had taken a vow to go on a crusade, Geoffrey of Joinville joined Geoffrey of Villehardouin, Matthew II of Montmorency and Simon IV of Montfort-l'Amaury approached Duke Odo III of Burgundy, asking him to fulfill Theobald's vow and lead a crusade. Odo refused, and Geoffrey was nominated to make the same request to Count Theobald I of Bar, who also refused.
Later in 1201, in preparation for his own crusade, Geoffrey made gifts to the Abbey of Clairvaux, the church of Saint-Laurent in Joinville and the men of Watrignéville subject to the Abbey of Saint-Urbain, which was a neighbour of Joinville. In the last two of these donations, he makes explicit reference to his intention to go to Jerusalem and visit the Holy Sepulchre. His presence with the main crusader army, however, is unrecorded. Geoffrey of Villehardouin in his account make no mention of the lord of Joinville after the failed negotiation with the count of Bar. He does not name him as one of the crusaders who split from the main army at Piacenza and went to Syria via the ports of Apulia, although it is possible he did go this route. His younger brother Robert, lord of Sailly, who was in Champagne preparing for his crusade in 1201, joined the army of Walter III, Count of Brienne, but died in Apulia en route in 1203.