New case-finding opportunities are needed to achieve hepatitis C virus (HCV) elimination in England by the year 2030. HCV antenatal testing is not offered universally in England but is recommended for women with risk factors for HCV (e.g. injecting drug use, being born in a high-prevalence country). The aim of this analysis was to investigate the missed opportunities for HCV antenatal testing among women who had given birth and were subsequently diagnosed with HCV at some time after childbirth. By linking data on live births (2010-2020) to laboratory reports of HCV diagnoses (1995-2021), we identified all women who were diagnosed with HCV after the date of their first childbirth. This group was considered to potentially have experienced a missed opportunity for HCV antenatal testing; HCV-RNA testing and treatment outcomes were also obtained for these women. Of the 32,295 women who gave birth between 2010 and 2020 with a linked diagnosis of HCV (median age: 34 years, 72.1% UK-born), over half (n = 17,123) were diagnosed after childbirth. In multivariable analyses, the odds of being diagnosed with HCV after childbirth were higher in those of Asian Bangladeshi, Black African or Chinese ethnicity and among those born in Africa. Over four-fifths (3510/4260) of those eligible for treatment were linked to treatment, 30.7% (747/2435) of whom had a liver scarring level of at least moderate and 9.4% (228/2435) had cirrhosis. Given the potential opportunity to identify cases of HCV with targeted case-finding through antenatal services, universal opt-out testing should be considered in these settings.