Noncommunicable diseases (NCDs) are the leading causes of death worldwide. Diabetes is one of the top four NCDs. More than 90% of cases are type 2 diabetes. Therefore, there has been a search for new methods to reduce the glycaemic index of commonly consumed foods without undesirable changes in organoleptic properties, such as the fortification of starchy foods with pure polyphenolic compounds. The aim of this study was to evaluate the effect of polyphenols, which are commonly present in food raw materials, on the digestibility of wheat starch and its glycaemic index value. The following polyphenols were added individually to the starch: p-coumaric acid, trans-ferulic acid (from phenolic acids), hesperidin, naringenin (from flavanones), (+)-catechin, epigallocatechin gallate (from flavanols), quercetin, and kaempferol (from flavonols), at 5, 10, and 20 mg. Then, 5% starch gels were prepared to be digested in the presence of amylolytic enzymes. The amount of glucose formed by hydrolysing starch was determined spectrophotometrically. These were used to determine the contents of RDS (rapidly digestible starch), SDS (slowly digestible starch), RS (resistant starch), TS (total starch), and SDI (starch digestion index), and to estimate glycaemic index (eGI) values. Concerning RDS, TS contents, and eGI, the lowest values were obtained with the addition of 20 mg of epigallocatechin gallate (p<0.05). The addition of 10 mg of kaempferol resulted in the highest SDS and RS contents, and the lowest SDI value (p<0.05). In general, the addition of epigallocatechin gallate at 20 mg and kaempferol at 10 mg had the greatest effect on the digestibility and estimated glycaemic index of wheat starch.