Nutritherapy is the art of using nutrients as a means of preventing or correcting dysfunction in the body. We aimed to evaluate the protective effect of dill fruit aqueous extract (DFAE) against acetic acid-induced ulcerative colitis. Healthy male rats (N = 42) were divided into seven groups of six animals each, with groups 1 and 2 being controls, groups 3, 4, and 5 given increasing doses of DFAE (50, 100, and 200 mg/kg, b.w., p.o.), and groups 6 and 7 were given sulfasalazine (100 mg/kg, b.w., p.o.) and gallic acid (50 mg/kg, b.w., p.o.), respectively, during 10 days. In vitro, we found that DFAE's IC exhibited a significant antioxidant capacity due to its high phenolic content. The in vivo studies showed that the pre-treatment with DFAE significantly reduced AA-induced morphological and histopathological alterations of the colonic mucosa. The antioxidant and anti-inflammatory power of DFAE maintained the redox equilibrium and preserved the intracellular mediators' homeostasis. Our data may suggest that dill fruit is a promising candidate for treating ulcerative colitis by controlling oxidative stress and inflammation.