This chapter considers the history of intellectual property law and microorganisms, with a special focus on microalgae. The chapter considers the evolution of international intellectual property, and its treatment of microorganisms. It explores the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure 1977. It also notes the requirement in the TRIPS Agreement 1994 for nation states to provide protection of microorganisms under patent law. It also contemplates the international regime for access to genetic resources, informed consent, and benefit-sharing. This chapter considers the ramifications of the landmark Diamond v. Chakrabarty decision, which considered patent law and microorganisms, and subsequent judicial consideration, and Congressional debate over the topic. The chapter considers patent landscapes and surveys in respect of microalgae. In particular, it looks at data analysis conducted in respect of the patent databases of the World Intellectual Property Organization, the United States Patent and Trademark Office, the European Patent Office, and IP Australia. This chapter explores patent litigation in respect of microalgae. In particular, it considers the recent action by DSM in the United Kingdom, filing a patent infringement lawsuit against Mara Renewables Corporation and Algal Omega-3 Ltd to protect algal lipids. This chapter notes the patent exceptions, limitations, and defences available to deal with public policy concerns in respect to access to microalgae. This chapter also considers the application of microalgae derived products in the fields of health, energy, and food and nutrition. It explores the potential of microalgae for sustainable innovation—particularly in light of the United Nations Sustainable Development Goals.