THIS STUDY was conducted to evaluate different priming treatments for wheat grains, including Nostoc muscorum and Arthrospira platensis aqueous extracts, for different periods (2, 6, and 12h). Priming treatments of 12 h promoted growth of the emerging wheat seedlings (shoot and root length and fresh and dry weight). Pigment, carbohydrate, and protein contents also improved in response to different priming treatments. The highest estimates of all measured parameters were recorded with A. platensis aqueous extract, followed by N. muscorum aqueous extract and finally for tryptophan (as a synthetic growth stimulator). Biochemical analyses of A. platensis aqueous extract showed the presence of secondary metabolites, such as phenolic and flavonoid compounds. Such compounds may be responsible for the antioxidant activity of A. platensis aqueous extract, which was determined using 2,2-diphenyl-1-picrylhydrazyl, hydrogen peroxide, and phosphomolybdenum radical scavenging assays. Furthermore, A. platensis aqueous extract was subjected to gas chromatography–mass spectroscopy (GC-MS) analyses, which indicated the presence of different bioactive compounds in this extract, mainly 2-pentanone, 4-hydroxy-4-methyl-, 3,7,11,15-tetramethyl-2-hexadecane-1-ol, and 3-amino-2,3-dihydrobenzoic acid. These components, in addition to others detected, may act synergistically to promote the growth of wheat seedlings.