The prevalence of type 2 diabetes mellitus (T2DM) is internationally ever-growing. Therefore, prevention, diagnostics, and control of insulin resistance and T2DM are of increasing importance. It has been suggested that mechanisms leading to insulin resistance and diabetes and its complications include high intake of refined and energy-rich food, which is presumed to be accompanied by suboptimal intake of trace elements, such as zinc (Zn), selenium (Se), chromium (Cr), and copper (Cu), which are essential and crucial for various biological processes. The purpose of this review is to highlight the role of Zn, Se, and Cu in T2DM. Diabetes seems prevalent when Zn, Se, and Cu are deficient, which may result from excessive intake of refined food. The literature search was conducted in PubMed and Scopus, supplemented with the reference lists of relevant articles and a Google Scholar search. We critically assessed all relevant citations, both review and research papers in English. The search terms that were used included Zn, Cu, diabetes, and diabetes mellitus. Research has shown that Zn, Se, and Cu are involved in the pathogenesis of diabetes, but these trace elements can in excessive amounts be toxic. Zinc appears to activate key molecules that are involved in cell signaling, which maintain the homeostasis of glucose. Zinc also regulates insulin receptors, prolong the action of insulin, and promote healthy lipid profiles. Copper in excess can create oxidative stress, which is a factor in the onset and the progression of T2DM. Abnormal Zn and Cu metabolism appears to accompany and may also cause diabetes complications.