Butterfly pea (Clitoria ternatea L.) is used for production of herbal teas, herbal juices and having a potential to use in culinary purposes. Even though, it is grown widely in Sri Lanka, comprehensive information and studies conducted on three popular varieties are still lacking. Hence, the aim of this study was to evaluate the elemental compositions, phytochemical properties of three C. ternatea L. flower varieties grown in Sri Lanka; white flower with normal keel petals (WSPF), blue flower with normal keel petals (BSPF), and blue flower with enlarged keel petals (BMPF). Total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP) and DPPH radical scavenging activity in aqueous extracts of C. ternatea flowers were determined using spectrophotometric methods. Kjeldahl method was used to determine the nitrogen content and crude protein % was calculated by multiplying the nitrogen content by a standard factor. Phosphorus content (UV spectrophotometer) and calcium and potassium contents (flame photometer) of the flower samples were measured by using a general mineralization procedure.The maximum TPC and highest level of TFC were reported in BMPF (31.88 mg GAE eq./g dry weight and 15.96 mg quercetin eq./g dry weight of flower) whereas FRAP of WSPF was significantly lower (10.66 mg trol eq./g dry weight of flower). FRAP of BSPF (14.56 mg trol eq./g dry weight of flower) and BMPF (18.50 mg trol eq./g dry weight of flower) were not significantly statistically different. BSPF showed significantly highest level of DPPH radical scavenging activity that was 11.97 mg trol. eq./g dry weight of flower. Meanwhile, the DPPH radical scavenging activity of BMPF and WSPF were not significantly different to each other. Mean P content was highest in WSPF and was lowest in BMPF (4.65 and 4.19 mg/g respectively). The N content was significantly higher (p<0.05) in both BSPF and WSPF (43.12 mg/g and 42.35 mg/g respectively). Significantly higher (p<0.05) mean protein contents were detected for BSPF and it was 26.95%. This is the first such detailed report on chemical composition and antioxidant properties of three main C. ternatea flower varieties grown in Sri Lanka.