Human contact can positively alter kennelled dog behaviour. Dogs often instigate social contact with people, but it is unclear what type of human contact is preferred. This study assessed the effect of familiarity of the human on interaction by kennelled dogs. Two populations were studied: dogs in long stay enriched (LSE) kennels (N=23; three breeds), born on site or brought in at ~9 weeks old; dogs in rehoming (RH) kennels (N=25; three breed size groups) entering the kennel as adults. Volunteers (classed as unfamiliar or familiar to each dog) entered the pen and sat for 10 minutes. If the dog was 'next to' (within arms' reach) they petted and spoke to the dog, otherwise they ignored the dog. The two most behaviourally distinct time periods, 0-2min and 8-10min, were analysed. LSE dogs spent more time 'next to, facing' the unfamiliar (mean=42.7±4.2s) than the familiar person (33.7±4.0s) at 0-2min (Wilcoxon Z=2.345, P=0.019), whilst spending longer 'far away' from the familiar (29.8±7.1s) than the unfamiliar person (12.6±4.0s) at 8-10min (Z=2.199, P=0.028). Breed differences were only evident at 8-10min and when the person was familiar. RH dogs spent longer 'next to, facing' familiar (50.5±4.5s) than unfamiliar people (40.3±5.1s) at 0-2min (Z=2.354, P=0.019) whilst showing a tendency towards longer 'next to, away' unfamiliar (34.0±5.3s) than familiar people (23.2±3.5s) at 0-2min (Z=1.843, P=0.065). No breed group differences were observed. Findings for LSE dogs suggest preferences for unfamiliar people in dogs that receive high daily levels of human contact. RH dogs appear to value familiar and unfamiliar contact equally, but with unfamiliar people are more alert to their surroundings. Overall, preference for familiar or unfamiliar human contact appeared to be affected more by environment and past experience than breed. Therefore, the benefit of different forms of human contact is likely to differ between facilities.