This study investigated the use of ladle furnace slag fines (FLF) for soil stabilisation. It contributes to the current state-of-the-art by comparing the effects of FLF on engineering properties of clayey and sandy soils, evaluating the effects of different curing periods on mechanical performance of soil-FLF mixtures, and investigating the resilient behaviour of the stabilised tropical soils. The present experimental programme covers the characterisation of FLF and soils, compaction, unconfined compression, diametral compression, CBR, and resilient modulus tests of soil-FLF mixtures. FLF provided increases in mechanical properties of both soils in all tests. Some highlights are the improvements in the CBR index of the clayey soil from 8% to 44%, and the sandy soil from 7% to 140%, together with significant reductions in CBR swelling and improvements in the resilient behaviour. The benefits can be mainly attributed to improvements in cementitious reactions, cation exchange capability, and the filler effect provided by FLF.