Instruments measuring social support in parenting often only measure the source or type of support offered, or the perceived helpfulness of that support. They often do not indicate who is providing what type of support, or they include items that are not explicitly applicable to early parenting. Many existing measures also are not sensitive to modern parenting, potentially excluding important aspects such as the support of a stepparent or non-resident biological parent. The Early Parenting Support Network Questionnaire (EPSNQ) was developed then tested using a group of 341 primary caregivers of children under 2 who participated in the Growing Together: Early Parenting Experiences Study. The instrument provides information regarding support source types, with items relating to instrumental, emotional, and informational support. The potential support sources include Partner, Other Parent (a non-resident biological parent), Family, Friends, Childcare Professional, and Other. There is also a single item on a 5-point Likert scale related to Perceived Lack of Support. Statistical analysis was undertaken to assess construct and convergent validity using the existing Family Support Scale (FSS) and Depression Anxiety and Stress Scale (DASS-21). Validity and reliability were found to be adequate. Test-retest of a group of 36 participants indicated adequate reliability. The EPSNQ has utility as a validated and reliable measure of social support in early parenting with potential applications for both research and clinical purposes.