This study examined the effects of a minimum quantity lubrication (MQL) and a Cupric oxide- (CuO-) based nanofluid on Inconel 718 machinability. Additionally, by using an MQL CuO-based nanofluid during the turning process, Inconel 718’s tribological characteristics are optimised. The experimentation was done using the minimum quantity lubrication (MQL) method. With the aid of magnetic stirring and an ultrasonic bath process, CuO nanoparticles were dispersed in distilled water, sunflower oil, and soyabean oil to create nanofluid. Soyabean oil contains uniformly distributed CuO nanoparticles. All the experimental trials are designed based on the L18 Taguchi-based orthogonal arrays and performed on CNC turning under MQL and nanofluid environment. There are four input parameters that were selected at mixed level, namely, cutting speed, feed rate, weight % of CuO in the nanofluid, and flow rate to analyze surface roughness and tool wear. In addition to that, the response surface method was used to identify the optimum condition for better surface roughness and tool wear. Surface roughness and tool wear were measured using the surface roughness tester and toolmaker’s microscope, respectively. Experimental results observed that cutting speed and weight % highly affect surface roughness whereas cutting speed and flow rate affect tool wear. The predicted optimal values for lower surface roughness are 160 ml/hr flow rate, 92.99 m/min cutting speed, 3 weight % of CuO, and 0.1 mm/min feed rate and for low tool wear 80 ml/hr flow rate, 92.99 m/min cutting speed, 3 weight % of CuO, and 0.1 mm/min feed rate.