Recently, nanoemulsions have gained significant attention for their improved stability and their wide range of potential uses in the food industry. This study aimed to create a novel type of mayonnaise with 23.6% (w/w) of oil using ultrasound-assisted emulsification for 6 min to incorporate lupin protein (3.4%, w/w) in the nanoemulsion stabilized by a combination of citrus fibre (2.5%, w/w) and psyllium (0.3%, w/w) or modified starch (3.0%, w/w). Nanoemulsions were produced using a cold-water bath and characterised by their stability and structural properties and used for the production of the mayonnaise. Results showed that the use of lupin protein led to stable nanoemulsions for 50 days stored at 4 °C. The smallest mean droplet size for lupin protein was 505.5 ± 43.5 nm and a polydispersity value 0.434 ± 0.045. Then, the selected nanomulsion was used to produce mayonnaise at room temperature. Mayonnaise were characterised in terms of its rheological and morphological properties, and through sensorial evaluation. The texture of the plant-based formulations was very close to one commercial mayonnaise, with similar resistance to deformation. The consistency (k) and flow index (n) were similar between samples and indicate that the samples are viscous due to the considerable value of k. A sensory analysis with a panel of consumers showed that the proposed formulations had a similar organoleptic profile compared to the benchmark sample. However, the tests showed that formulation developed with fibres had a slightly lower overall liking score.Ultrasound seems to be an effective strategy for developing plant-based nanoemulsions, foreseeing their use in the production of mayonnaise.