Vast quantities of plastic waste (PW) have become an integral part of all developed and developing countries. Although recycling is considered the best way of disposing of waste plastic to the maximum extent, its non-biodegradable nature and low recycling ratio in developing countries have created an encouraging need to repurpose plastic waste for infrastructural projects. Utilizing plastic waste as an alternate construction material will significantly reduce the load of the existing landfills and assist in less consumption of virgin quarry materials. In this study, efforts were made to understand the effect of plastic fibre extracted from waste residue for modifying the mechanical properties of soils collected from Meghalaya. Waste plastic and commercially available geosynthetic fibres were cut into two different aspect ratios (AR1 and AR2) with sizes 10 mm × 2.5 mm and 20 mm × 2.5 mm, respectively. These are randomly mixed with soil in different proportions (0.1%, 0.3%, 0.5%, 0.7%, 1%, 1.5% and 2%). with varying aspect ratios (AR1 and AR2). Experiments have been conducted to understand the effect of plastic waste fibre as reinforcement on compaction, UCS and California bearing ratio values. Maximum dry density (MDD) has been achieved at 0.7% of plastic fibres and 0.5% of geosynthetic fibres content by dry weight of soil for AR1 and AR2. Adding plastic waste at the two aspect ratios increased the UCS of both soils by 22.6% and 18.44%, respectively. The CBR value of the soil showed judicious improvement in the soil. Plastic fibre of AR1 and geotextile fibre of 10 mm length have shown a similar influence on CBR value with a 10.07% increment in its value.