The objective of this research was to improve the volatile flavour profile of a pork trimming hydrolysate by lactic acid bacteria (LAB) fermentation. Five probiotic strains and one dairy strain were used. The dominant aliphatic aldehydes (80.90%) in the unfermented hydrolysate were greatly reduced to <15% by converting into respective carboxylic acids and alcohols after fermentation. Strain GG was the only LAB that produced a significant level of succinic acid (1.62 mg mL−1) and ketones (14.92%) (mainly diacetyl and acetoin) in the hydrolysate. Strains 299V and GG showed moderate proteolytic activities as their amino acid content reduced to 126.05 and 219.14 mg per 10 mL compared to the control (316.45 mg per 10 mL) after fermentation, respectively. However, little amino acid‐derived volatiles were found in all fermented samples. These findings indicate that LAB fermentation modulates the flavour compounds of pork hydrolysates, which has the potential to be developed to novel flavouring materials.