The NAD⁺-dependent protein deacetylase, sirtuin 1 (SIRT1), is thought to be a key regulator of muscle metabolism, although its precise role in regulating skeletal muscle insulin sensitivity is unclear. To address this, we generated a mouse model with muscle-specific overexpression (OX) of SIRT1 (mOX).  Our aim was to determine, 1) whether OX of SIRT1 alone enhances skeletal muscle insulin action, and 2) whether calorie restriction (CR) of mOX mice synergises CR-induced enhancement of muscle insulin action.  SIRT1 gene expression was ~100-fold higher in all muscle types (i.e., oxidative, glycolytic and mixed) in mOX vs. floxed/control (FLX) mice. This upregulation was coupled with enhanced SIRT1 deacetylase activity, as demonstrated by reduced acetylation of PGC1α and p53. Despite large-scale OX of SIRT1, ex vivo basal and insulin-stimulated (60 μU/mL) 2-deoxyglucose uptake in soleus (SOL) and extensor digitorum longus (EDL) muscles was not different between young (4 months) mOX and FLX mice. In addition, while 20 d of CR (60% of ad libitum [AL] intake) enhanced (~3-fold vs. AL) insulin-stimulated 2DOGU in SOL and EDL of FLX mice, there was no additive effect of CR in mOX mice. These results demonstrate that OX of SIRT1 does not enhance skeletal muscle insulin action in YG mice, and suggest that activating SIRT1 via pharmacological means may not be sufficient to enhance muscle insulin action.