Blocks are widely used in construction industry for both load and non-load bearing walls, blocks are of different forms and shapes and the most common is hollow sandcrete blocks. Glass wool fibre is an industrial waste product which can be turned to a useful material in the construction industry. The effect of glass wool fibre on the strength properties of hollow sandcrete blocks was investigated. Sieve analysis was done on the sand used. The batching of the materials were done by weight and the mix ratio used was 1:8 with an average water-cement ratio of 0.5. Block samples of 150×225×450 mm (6” block) were produced by hand moulding process. Glass wool fibre at 0%, 5%, 10%, 15% and 20% of cement were added to the mix and compressive strength test was done by the ADR Touch 1500 kN Compression Testing Machine on the block samples. The Coefficient of Curvature (Cc) and Coefficient of Uniformity (Cu) of the sand were 1.04 and 4.47 respectively, the sand is well graded. The compressive strength test results of an average of 0.6, 0.8, 0.9, 1.1 and 0.4 N/mm2 were obtained respectively. It was concluded that the compressive strength of the hollow sandcrete block gradually increased and attained the maximum strength at 15% addition of glass wool fibre which is 33% increase in the compressive strength, where the weight also decreased by 1.6%. Therefore, the block at 15% addition of glass wool fibre can be used for non-load bearing walls such as fence and partition walls in building construction.