Non-heat treatable 5XXX aluminium alloys have attractive properties such as weldability and corrosion resistance, but achieve only moderate strength and can suffer from sensitization. A potential route to improve both strength and reduce sensitization is to form an additional population of L1₂ dispersoid particles by introducing new dispersoid forming elements. In this study, novel 5XXX alloys with L1₂ dispersoid forming additions have been produced and analysed. To maximize the L1₂ dispersoid volume fraction as well as minimize cost, a combination of different dispersoid formers have been explored, namely zirconium, scandium, erbium, and yttrium. The effect of homogenization treatment on the precipitation of L1₂ dispersoids was studied to optimize the dispersoid size, volume fraction, and distribution. Two-step homogenization regimes, guided by a Kampmann Wagner Numerical (KWN) method precipitation model, were shown to precipitate many fine dispersoid particles, whose size and distribution through grains was studied using high resolution scanning electron microscopy (SEM). An Electron Probe Micro-analysis (EPMA) study was conducted to quantify the micro-segregation of elements upon casting and after the chosen homogenization treatments. EPMA data and Scheil-Gulliver simulations were used in conjunction with the KWN model to study the effects of micro-segregation on L1₂ dispersoid precipitation. The results show precipitation is highly dependent on position within grains and the local elemental concentration. The dispersoid precipitation model was coupled to a simple strengthening and work hardening model to understand the effect of L1₂ dispersoids on mechanical properties. The model predictions were compared with microstructural and tensile property measurements. It was demonstrated that a notable increase in both strength and work hardening was obtained in alloys with an optimized dispersoid distribution.