The formation of disinfection by-products (DBPs) following chemical disinfection is a major concern for water utilities, with factors such as climate change and altered land use likely to exacerbate the problem. Advanced pre-treatment processes can remove DBP precursors prior to disinfection, but processes that only remove natural organic matter and not halides can result in the formation of more toxic DBPs. To date, most studies assess the suitability of pre-treatment processes based on targeted analytically detected DBPs, with few studies considering toxicity. We conducted a literature review to assess how well pre-treatment processes can remove DBP precursors and reduce DBP formation potential and finished water toxicity, with five treatment categories considered: adsorption, advanced oxidation, biofiltration, ion exchange and membrane filtration. Only studies that assessed DBP formation following chemical disinfection with and without pre-treatment were included in the review, with changes in toxicity after pre-treatment predicted using iceberg modelling based on reported DBP concentrations. Adsorption processes, including granular activated carbon (GAC) and powdered activated carbon (PAC), as well as magnetic ion exchange (MIEX) and nanofiltration showed the best reduction of summed DBP concentration (average reduction of 64 to 78%). Despite good DBP reduction, all pre-treatment processes, apart from silver-based activated carbon, resulted on average in increased bromine substitution compared to untreated water. This was due to most pre-treatment processes removing more dissolved organic carbon than bromide. Silver-based activated carbon and MIEX yielded the best reduction of predicted toxicity based on iceberg modelling predictions due to greater reduction of brominated DBPs (average reduction of 73 to 84%). GAC and PAC are commonly used pre-treatment processes, but both showed lower reduction in predicted toxicity compared to summed DBP concentration. This demonstrates the importance of considering both DBP formation and toxicity when selecting advanced pre-treatment processes.