Objective Spontaneous vaginal births are often the presumed choice and represent 45% of UK births. However, information is inconsistently given about benefits and risks. This impacts decision-making and experience. A Core Information Set (CIS) is an agreed set of information points discussed prior to a decision. We aimed to develop a CIS for vaginal birth. Design Information points were identified from a literature search, patient information leaflets, interviews, and a survey. These informed a two-round Delphi survey, where stakeholders voted on the importance of items for inclusion. Items supported by >80% of participants were discussed by 28 parents and professionals at consensus meetings. The final CIS was populated with an engagement group ensuring accessibility. Setting The study took place in the UK, with participants recruited online. Population Pregnant and postnatal women, birth partners, healthcare professionals, medico-legal professionals and people working for interested/relevant organisations. Main outcome A CIS for vaginal birth. Results 77 information items were identified. In round 1 (631 participants) of the Delphi Survey, 84.5% were from the patient group and 15.5% from the professional group; in round 2 (228 participants), 74.3% were from the patient group and 25.7% from the professional group. 28 items met the criteria for consensus discussion. The final CIS includes 19 information points addressing: labour process, pain relief, labour complications, procedures or interventions during labour, experiences after birth, outcomes for the baby and environment during labour. Conclusions This CIS can be used to facilitate discussions and support informed decision-making about vaginal birth.