It is well known that if plastic wastes are not well managed, it has a negative impact on the environment as well as on human health. In this study, recycling plastic waste in form of strips for stabilizing weak subgrade soil is proposed. For this purpose, a weak clay soil sample was mixed with 0.2%, 0.3%, and 0.4% of plastic strips by weight of soil, and the experimental results were compared to the control soil sample with 0% plastic. Laboratory tests on the Standard compaction test, Unconfined compression test (UCS), and California bearing ratio (CBR) were conducted according to the American Society for Testing and Materials (ASTM). The results of the study reveal that there are significant improvements in the strength of weak soil stabilized with plastic waste strips. Accordingly, the Standard Proctor test shows that there is a small increment in the maximum dry density of the soil when it is mixed with plastic strips. The result from the CBR test shows that there is a significant increment of CBR value with the plastic strip content. The unconfined compressive strength test also shows that increasing the percentage of plastic strips from 0 to 0.4% resulted in increased strength of soil by 138% with 2 cm length plastic strips. Therefore, this study recommends the application of plastic strips for improvement of the strength of soft clay for subgrade construction in civil engineering practice as an alternative weak soil stabilization method.