Data is the most valuable fuel for marketing activities today. Thus, the level of competition in the markets has increased the importance of data in the airline industry, as in all other industries. With the development and spread of online technologies, the highly needed data by airlines started to be produced by consumers in online environments. In this regard, one of the shortest ways to determine the reactions and changes in consumer behavior phenomenon is to collect, process, and analyze big data that could be derived from consumer online activities. This chapter aims to provide a literature review on the application of online consumer-based big data in airline marketing and to create a research agenda. In this context, the current chapter presents the sustainable contributions of the use of big data in the airline industry. Moreover, big data analytics, web analytics, social media analytics, sentiment analysis, and search engine optimization are also presented in detail. Finally, the chapter concludes by presenting insights into the direction of online consumer data that airlines could leverage in their marketing efforts.