Like so many other professions, law is becoming increasingly influenced by an overwhelming amount of disparate, fragmented and complex data that can both help and hinder business. Data comes from a wealth of different sources, both internal and external, constantly changing, never still. Keeping control of all that data is one challenge; leveraging it to the greater good much harder. Other professions have had years of experience integrating data analytics into their businesses and using analytics to predict outcomes; for legal, this is a relatively new challenge, and one that could potentially change the way the industry works. Despite the huge amount of data in the average law firm, data-driven decision-making is relatively new and uncharted. With the knowledge that some 90 percent of data in the world today was created in the last two years, this needs to change. Building the data-driven law firm looks at how the use of data has become inextricably linked with the practice of law; how it can be utilized to the good and the safeguards that must be put in place to mitigate the bad; how Big Data will revolutionize the way lawyers work, and the cases they will work on; and how new uses for data (including blockchain and the Internet of Things) will influence the law firm of the future.