Low energy, higher fiber diets (HFD) are becoming more prevalent in the US swine industry due to fluctuating corn-soy diet prices. In sows, HFD are reported to increase satiety and reduce stereotypic behavior, aggression, and activity. However, little is known about how fiber content in diets contributes to behavioral reactivity in grow-finish pigs. Therefore, the objective of this study was to determine if diet influences behavioral reactivity using a human approach test (HAT) and novel object test (NOT). We hypothesized that pigs reared on HFD would be less reactive to HAT and NOT compared with pigs reared on high energy, low fiber corn-soy diets (CD). Forty Yorkshire barrows (48 ± 8 kg BW) were randomly allocated to 2 treatments: HFD (n = 20) and CD (n = 20). The barrows were evaluated once using HAT and once using NOT utilizing a crossover experimental design. Each pig was individually tested within a 4.9 × 2.4 m test arena for 10 min between 1300 and 1900 h. Behavior was evaluated using live and video observations. The video was watched continuously by one trained observer for latency, frequency, and duration of human and novel object (orange traffic cone) touches, frequency of escape attempts, frequency of freezing postures, activity (number of arena line crossings), urination, and defecation. Data were analyzed using the Glimmix procedure of SAS with fixed effects of diet and test week, covariate of body weight, and random effect of pen. Diet did not alter latency to first touch, touch frequency, or duration of touches with the human or novel object (P > 0.10). Similarly, frequency of escape attempts, freezing, activity, and urination did not differ between diets during HAT or NOT (P > 0.10). Barrows fed HFD defecated more during NOT (P = 0.01), and tended to defecate more during HAT compared with CD barrows (P = 0.06). Differences in defecations are likely due to high fiber content of HFD resulting in more waste excretion. These results suggest that feeding high fiber diets did not alter grow-finisher barrow behavioral reactivity.