Two lick suppression studies were conducted with water-deprived rats to investigate the influence of spatial similarity in cue interaction. Experiment 1 assessed the influence of similarity of the spatial origin of competing cues in a blocking procedure. Greater blocking was observed in the condition in which the auditory blocking cue and the auditory blocked cue originated at the same spatial location. Recent investigations have demonstrated that manipulations that impact competition between cues trained together have similar effects on interference between cues trained apart. Therefore, Experiment 2 investigated the influence of similarity of the spatial origin in proactive interference of Pavlovian conditioning by separately pairing two auditory cues with a common outcome, originating at the same spatial location or different spatial locations. Greater proactive interference was observed in the condition in which the interfering cue and target cue originated at the same spatial location. The results are considered in light of the possibility that a similar mechanism may underlie interference between cues trained apart and cue competition between cues trained together.