Abstract Online respondent-driven detection (online-RDD) is a novel method of case-finding that may enhance contact tracing (CT). However, the opportunities and barriers of online-RDD for public health practice have not yet been investigated from the perspective of public health professionals (PHPs). Therefore, it is unclear what the potential strengths and limitations of online-RDD for CT are. We conducted a sequential exploratory mixed methods research. First, we conducted semi-structured interviews with Dutch PHPs involved in CT. Questions were derived from the diffusion of innovations theory. Second, we distributed an online-questionnaire to 260 Dutch PHPs to study the main findings in a larger population. We used hypothetical scenario’s (scabies, shigella, and mumps) to elicit PHPs’ perceptions of online-RDD. Twelve interviews were held. Response rate to the online-questionnaire was 31% (n = 70). Four themes related to characteristics of online-RDD that influenced PHPs’ intention to adopt online-RDD emerged: advantages over traditional CT, task conflicts and opportunity costs, public health risks, and situational compatibility. PHPs believed online-RDD may enhance CT through increased reach, low-key communication options, and saving time. Limitations were foreseen in the delivery of measures, supporting patients and contacts, missing information and contacts, and causing unrest. Online-RDD may be particularly applicable in situations with digitally skilled and literate target populations, low urgency, low time-pressure, and a simple perspective for action. A majority of PHPs (70%) had a positive adoption intention towards online-RDD. PHPs perceived online-RDD as beneficial to public health practice. Further development of online-RDD should focus on facilitating opportunities for personal contact between PHPs, patients and contacts. A comparative study of ‘traditional’ CT and online-RDD could yield further insights in the potential of online-RDD for public health practice.