Antirrhinum majus (snapdragon), a perennial plant from the Scrophulariaceae, is valued for its ornamental and biochemical traits. This study investigates the effects of various LED light spectra (white, blue, red, 80% blue + 20% red, 60% blue + 40% red, 40% blue + 60% red, 20% blue + 80% red) and single-walled carbon nanotube concentrations (0, 50, 100 mg/L) on photosynthesis efficiency, morphological growth, and biochemical properties of this plant. The experiment was conducted using a completely randomized factorial design with four replications. Data were analyzed using SAS software with Duncan’s test. Results revealed significant effects of light and carbon nanotubes on morphological (flower number, plant height, fresh weight, flower diameter) and biochemical traits (sugar content, flavonoids, phenols, antioxidants, anthocyanins), as well as chlorophyll fluorescence parameters (Fm Fv, and Fv/Fm). The highest flower number (23) was observed under 100% red light without nanotubes, while the maximum fresh weight (41.46 g) was recorded under 20% red + 80% blue light. Blue light combined with 50 mg/L nanotubes maximized stem and flower diameter, whereas biochemical properties and Fv/Fm were optimized under blue-red combinations with 100 mg/L nanotubes, with the highest Fm and Fv under 40% red + 60% blue light. The findings suggest that red light alone enhances growth, without the need for nanotubes. In contrast, blue-red combinations with 100 mg/L nanotubes were more effective for improving biochemical traits and photosynthesis efficiency. The heat map analysis of trait correlations indicated a strong positive relationship among the evaluated traits.