The A1103 is a primary short cut avoiding the Lincolnshire town of Market Rasen. Originally the B1204, the road gained its current number in the late 1920s.
The road starts on the A631 east of Blackbridge, as it turns south to West Rasen; the A1103 takes that road's alignment and primary status. The road heads east across the open fields. It is flat with the occasional bend and passes a few buildings (although the village of Osgodby is to the north) and the occasional side road. Presently the road reaches Osgodby Moor, which is partly wooded. It ends at a crossroads on the A46 to the north of Market Rasen. The road ahead to Walesby is unclassified.