Seaweeds are the essential plant growth bio-stimulants due to their high composition of phenols, flavonoids, polysaccharides and antioxidant compounds. Seaweed extracts stimulated the seed yield, seed germination, plant growth parameters, biometric attributes, thousand grain weight, plant height, protein and fat composition in Agricultural and Horticultural crops which were increased. Foliar application, soil application or seed treatment of seaweeds against various phytopathogens including biotic such as fungi, bacterial, nematode and mesobiotic pathogens like viral diseases as well as insects has been confirmed by many scientific reports. They are mostly used as a powder and some times available also as a liquid form. They are having the mode of action of inducing systemic resistance, bio-protectant activity by induced or combined activity of microbial biota and enhancing crop yield. This review explains about the role of seaweed extracts for plant diseases management strategies.