Salt stress is one of the most serious factors that influence the plant growth and yield. The extensive use of chemical fertilizers caused an increase in land contamination and hence effects on human health. The use of biofertilizers can solve these problems. In the present work, different concentrations of Spirulina platensis liquid extracts (SLEs; 1%, 2%, and 4%) were used to enhance seeds germination, seedling growth, length of radical, number of leaves, and plant height of T. aestivum L. S. platensis liquid extract (SLE) 2% was chosen to test against salt stress with 10% and 25% seawater in T. aestivum L. watered. The growth parameters such as shoot, root, length, fresh, dry weight, leaf width, number, and area were used to estimate the effects of 2% SLE against salt stress caused by seawater. Also the carbohydrate, protein, phenol, and total antioxidant contents were measured in T. aestivum L. treated with 2% SLE in combination with seawater and watered with different concentrations with seawater alone. The results denote that the best concentration of SLEs was 2%, which promoted the germination growth of T. aestivum L. in comparison to control and other concentrations. SLE (2%) enhanced the carbohydrates, protein, total phenol contents, and antioxidant contents of T. aestivum L., treated with seawaters (SW10% and SW25%) and SLEs in comparison to T. aestivum L. SW 10% and 25% alone. S. platensis liquid extract (SLE) can be used as biofertilizer to enhance the growth and phytochemical contents of T. aestivum L. and to make tolerance of T. aestivum L. against salinity.