The antioxidant activity of Stachys maritima was determined via initial tests, yielding a DPPH IC50 value of 0.114 ± 0.001 mg/mL, indicative of its ability to neutralize free radicals and mitigate oxidative stress. Moreover, the plant extract demonstrated a significant iron chelation capacity comparable to EDTA (IC50: 5.98 ± 0.10 mg/mL). Analysis of the extract revealed high levels of flavonols, flavonoids, phenolic compounds, proanthocyanidins, and tannins, notably totaling 1039.48 ± 6.53 mg GAE/g and 276.21 ± 4.38 mg CAE/g, respectively, contributing to its robust antioxidant potential. ST‐CQDs, nanoscale carbon structures, have garnered interest in biomedicine for their antioxidant properties. Confirmatory analyses showed their high antioxidant activity with DPPH IC50 value of 0.69 ± 0.03 mg/mL and iron chelation capacity of 3.86 ± 0.41 mg/mL. Antimicrobial tests revealed S. maritima efficacy against various pathogens, while ST‐CQDs showed no effect. High peak areas in analyses suggest specific compounds' presence, notably certain fatty acids, highlighting their crucial role in composition understanding. Notably, 9,12,15‐Octadecatrienoic acid's importance is underscored. These findings provide a significant basis for further exploring TNF development's molecular mechanisms.