Currently, the cultivation of chia has expanded globally owing to its abundance of nutrients and bioactive compounds. This study aimed to explore the nutritional profile, fatty Acid composition, flavonoids (TFC), and antioxidant activity (AA) of chia seed (Salvia hispanica) cultivated under the climatic conditions of the Siberian region compared with flax seed (Linum usitatissimum) and psyllium husk (Plantago ovata). Additionally, the influence of different green solvent (water:ethanol) ratios on the TPC, TFC, and AA was examined. Results demonstrated that chia seeds have considerably greater dietary fiber (27.50 ± 0.021%) and protein contents (23.50 ± 0.015%) compared to flax seed and psyllium husk (P < 0.05). The major fatty acid were found to be α-Linolenic acid in chia seed, flax seed and psyllium husk extract were found to be with relative percentages of 62.65%, 52.40%, and 59.66%, respectively. Chia seed also demonstrated considerably greater TPC (2.17 ± 0.08 mg GAE/g), TFC (1.08 ± 0.20 mg QE/g), and AA (88.13 ± 0.11) than flax seed and psyllium husk (P < 0.001). The measurement of phenolic compounds will be provided in this section whenever the results are available. Pearson’s correlation (R2 = 0.987) demonstrated a substantial link between TFC and their respective AA. This study revealed that chia seed extracts accumulate a tremendous number of nutritional profile and phytochemicals, as well as demonstrate excellent antioxidant activity. Therefore, it is important to consider the possibility of cultivating chia seeds in the Siberian area since the climatic conditions do not have an effect on the nutritional and phytochemical components of the seeds.