Metabolic dysfunction-associated fatty liver disease (MAFLD) and diabesity (diabetes related to obesity) are interrelated since glucose and lipid alterations play a vital role in the development of both disorders. Due to their multi-variant metabolic features, more than one drug or natural product may be required to achieve proper therapeutic effects. This study aimed to evaluate the effectiveness of a formulation containing co-micronized palmitoylethanolamide and rutin (PEA-Rut) associated with hydroxytyrosol (HT), namely NORM3, against hepatic damage and metabolic alterations in high-fat diet (HFD)-induced diabesity in mice. NORM3 decreased the body weight and fat mass of obese mice. The formulation improved HFD-altered insulin sensitivity and hepatic glucose production and metabolism, as shown by glucose, insulin, pyruvate tolerance tests, Western blot, and real-time PCR. In the liver, NORM3 limited macro- and micro-vacuolar steatosis, as revealed by morphological analysis, and reduced the associated hepatic inflammation. NORM3 counteracted lipid dysfunctions of HFD animals, activating AMPK, a key cellular energy sensor, and normalizing the expression of carnitine palmitoyl-transferase (CPT)1, a rate-limiting enzyme of fatty acid β-oxidation, and other genes involved in lipid homeostasis. Relevantly, the hepatic antioxidant activity of NORM3 was proved (reduced ROS and increased detoxifying factors and enzymes). Finally, in vitro synergistic protective effects of the components (PEA-Rut and HT) on H2O2-induced oxidative challenge in HepG2 were determined (ROS production, inflammation, and antioxidant defense). Our results show the beneficial effect of NORM3 and its potential as an innovative phytotherapeutic combination in limiting hepatic damage progression and counteracting glucose and lipid dysmetabolism associated with diabesity.