Background This study aimed to compare the effects of sesame (SO), canola (CO), and sesame‐canola (SCO: a blend) oils on glycaemic control markers and liver function enzymes in adults with type 2 diabetes. Methods In this randomized, triple‐blind, three‐way, cross‐over clinical trial, participants replaced their usual oil with the intervention oils for 9 weeks. Serum fasting blood sugar, fasting serum insulin (FSI), insulin resistance (HOMA2‐IR), beta‐cell function (HOMA2‐%B), insulin sensitivity (HOMA2‐%S), quantitative insulin sensitivity check index (QUICKI), as well as serum liver function enzymes were measured at baseline and end of intervention periods. Results Ninety‐two participants completed all treatment periods. After adjusting for confounders, all treatment oils resulted in significant improvements in FSI and HOMA2‐%S (p < 0.05). SO and SCO led to favourable changes in HOMA2‐IR and QUICKI (p < 0.05). Following CO and SCO, there was a significant decrease in HOMA2‐%B (p < 0.05). The sex‐stratified analysis revealed that FSI and HOMA2‐IR were decreased after SO compared to CO in males (p = 0.024). Serum gamma‐glutamyltransferase (GGT) was significantly lower following SO compared to CO in females (p = 0.02), however, the difference in change values was not significant (p = 0.058). Conclusions SO consumption appears to improve glycaemic control markers in males and serum GGT in females compared with CO in patients with type 2 diabetes (registration code: IRCT2016091312571N6).