Neonatal Jaundice is a common condition in newborns caused by excess bilirubin accumulating in the blood. Bilirubin is a neurotoxin and if left untreated can cause permanent neurological impairment or death. Jaundice resulting from unconjugated hyperbilirubinemia can be easily treated using blue light phototherapy, and several low-cost treatment systems have been built for low-resource settings. However, there is still a lack of an appropriate low-cost diagnostic. To address this, we present BiliSpec, a low-cost paper lateral flow disposable and reader to measure total bilirubin from whole blood. The system can be used at the point-of-care and measure bilirubin concentration within minutes. The accuracy correlates well with a reference laboratory standard (r = 0.996). We then performed a pilot clinical study using BiliSpec at Queen Elizabeth Central Hospital in Blantyre, Malawi. Bilirubin concentrations measured with BiliSpec correlated well with a laboratory reference standard in a 94 patient study (r = 0.973). Bilirubin concentrations measured ranged from 1.1 mg/dL to 23.0 mg/dL. The mean difference between BiliSpec and the laboratory standard was 0.3 mg/dL (95% CI: −1.7–2.2 mg/dL).