Introduction: Oral health is a loyal part of general health. As per the World Health Organization (WHO), dental caries is the most widespread noncommunicable disease and is a significant universal public health concern. The main causative organism associated with this disease is Streptococcus mutans (S. mutans). Various synthetic agents like chlorhexidine and fluorides are commercially available to prevent dental caries. However, these have side effects. Presently, research is engaged in the use of plant extracts to develop an effective and biocompatible material that may be used safely in the oral cavity. Methodology: Four plants were collected—Emblica officinalis, Vitis vinifera seeds, Psidium guajava (P. guajava) Linn leaves, and Acacia nilotica (A. nilotica), and extracts were prepared individually. These extracts were subjected to phytochemical analysis, and bacterial growth and fermentation were assessed. Result: The level of significance was set at p < 0.05. All the plant extracts inhibited S. mutans growth at all serial dilutions except P. guajava Linn and A. nilotica showing 55 CFU/mL and 5 CFU/mL, respectively in 1/1000 dilution only. The phytochemical analysis confirmed that all four plant extracts had alkaloids, carbohydrates, tannins, and flavonoids. Steroids and proteins are present in P. guajava Linn. Proanthocyanidins were present in Vitis vinifera. Saponins and Anthraquinones were present in A. nilotica exclusively. Conclusion: All the extracts were effective against S. mutans. These could be tried as herbal alternatives to conventional adjuncts. However, these results must be additionally evaluated for toxicity in animal models, and effectiveness must be assessed using in vivo studies on human subjects.