This research addresses life cycle environmental and economic sustainability in the baby food sector. In the UK, this sector has been growing rapidly, expanding by around 30% between 2009 and 2014, by which time it was worth an estimated Â£181 million per year. This growth sits within a context of high emissions from the food sector: in 2015, UK net GHG emissions were estimated to be 496 million tonnes (Mt) and the domestic food chain was responsible for 115 Mt CO2 eq. emissions. However, within this overall food chain, very little is known about the sustainability of the baby food sector, with almost no prior literature in the area. The research presented here begins with market research to identify the characteristics of products available in the ready-made food market, in which wet and dry products in jars and pouches dominate sales. Subsequently, 12 representative products are selected from those available on the market and each is assessed in detail to establish its environmental and economic impacts using life cycle assessment (LCA), life cycle costing (LCC) and value added (VA) assessment. The findings of these product-level assessments are then compared to home-made equivalents and finally scaled up according to sales volumes to provide an overall view of the baby food sector as a whole. Wet and dry variants of ready-made porridge products are assessed first as the most commonly consumed breakfast option. The dry product is shown to have 5%-70% the impacts of the wet, on average, and the importance of product formulation is clear: for dry porridge, reformulation could reduce impacts by up to 67%. For the wet porridge, switching from glass jars to plastic pouches is also shown to decrease impacts by up to 89%. Assessment of 11 wet ready-made products demonstrates that the highest impacts are found in spaghetti Bolognese and salmon risotto, and that raw materials are the major hotspot of the life cycle, contributing 12-69%, followed by manufacturing at 2-49%. When combined into a range of weekly diets limited differences are observed between diets, except in cases where dairy-free diets result in compensatory increases in meat consumption. When the aforementioned selection of ready-made products is compared to its home-made equivalent, the home-made options are shown to have lower impacts by 50% to 17 times. This is due to the avoidance of manufacturing and extra packaging stages, as well as shorter supply chains resulting in less waste overall. At the product level, the LCC of ready-made meals ranges from Â£0.08 to Â£0.26 per 125 g product, compared to Â£0.02-Â£0.20 for the home-made equivalents. Value added is, on average, approximately four times higher for ready-made meals than homemade, illustrating the potential profit of the sector. Annually, the ready-made baby food sector has an LCC of Â£40m and carbon footprint of 109 kt CO2 eq. This carbon footprint represents only 0.1% of the UK food and drinks sector. The results of this research show that considerable improvements can be made to the environmental and economic sustainability of baby foods, both ready- and homemade, while home-made options tend to have lower costs and environmental impacts. The outputs provide benchmarking and improvement opportunities for industry and government, as well as insight for consumers.