Arnold II of Isenburg-Braunsberg (? - 5 November 1259) was the Archbishop of Trier from 1242 until 1259.

Arnold was born as a son of Count Bruno II of Isenburg-Braunsberg and Theodora of Wied. In 1217 he became an archdeacon of the cathedral of Trier, and was made a cathedral provost in 1228. Arnold was elected the Archbishop of Trier in 1242. However the Emperor had appointed Rudolph of the Brücken as archbishop, and had granted him the regalia. A civil war between the two candidates ensued, and it was not until Rudolph renounced the archbishopric and Pope Innocent IV confirmed Arnold on 23 January 1245 that the fighting ceased.

Arnold had elected, rival to the Hohenstaufen Emperors Frederick II Stupor Mundi and Conrad IV, Henry Raspe (1246 - 1247), William of Holland (1247 - 1256) and Alphonse X the Wise of Castile (1257 - 1273) German kings, which led to much controversy and warfare. During his reign Arnold had to contend with powerful Robber Barons, and despite their threat he constructed several castles and fortresses along the Rhine.

Arnold died in Montabaur and was buried in Trier Cathedral.

Preceded by:

Arnold II of Isenburg-Braunsberg

Succeeded by:

Theodoric II of Wied Archbishop of Trier
1242 - 1259
Henry II of Finstingen