This paper explores the current applications and associated issues surrounding Big Data in tourism research. Following a brief introduction of Big Data, we explore common Big Data sources and their methodologies for tourism studies including search engine data, webpage and booking data, user generated content (UGC), and device data. We identify opportunities, challenges and recognized concerns Big Data brings to tourism research. Using Canadian Federal legislation as an example, we then explore broader challenges associated with access and use of Big Data in tourism, including issues of ethics and judicial challenges related to privacy laws and legislation. We conclude with speculation what possibilities Big Data will bring to tourism research going forward.