Andy Johnson-Laird (born February 1945) is an English-American computer scientist. He was the president of digital forensics firm Johnson-Laird Inc. in Portland, Oregon, where he lived with his wife, Kay Kitagawa.

Johnson-Laird was born in Sheffield in England in February 1945.^{[citation needed]} He was educated at Culford School and then attended the Regent Street Polytechnic, now known as The University of Westminster. Johnson-Laird also has lived in Ferney-Voltaire (France), Toronto (Canada), and San Jose, (Northern California).^{[citation needed]}

Johnson-Laird's computer career started in 1963 at National Cash Register Company's London offices where he worked as a computer operator and taught himself to program the NCR 315 mainframe computer during the night shift. He was then invited to teach as a lecturer in NCR's Computer Education department, teaching NCR customers how to program. Subsequently, he wrote system software for the NCR-Elliott 4100 mainframe computer. Johnson-Laird also worked as a systems programmer for Control Data Corporation in Ferney-Voltaire in support of supercomputer installations at CERN. and various universities in Europe. He transferred to Control Data Corporation's Toronto Development Facility in 1977.^{[citation needed]}

In the late 1970s, Johnson-Laird applied his knowledge of mainframe computers to the emerging hobbyist personal computer market. He purchased and hand-built a SOL-20 personal computer from Processor Technology, and a Cromemco Z-2 as test platforms.^{[citation needed]}

Johnson-Laird's 1979 immigration to the United States resulted in litigation over "a legal issue of first impression" concerning "the proper interpretation of section 101(a)(15)(L) of the Immigration and Nationality Act, 8 U.S.C. s 1101(a)(15)(L), which allows 'a firm or corporation or other legal entity' to petition for the granting of 'non-immigrant' status to employees which it wishes to transfer to corporate posts in this country". Johnson-Laird was successful in his challenge to the agency's interpretation of this rule to not permit a petition for an "L" visa by a sole proprietorship. Johnson-Laird was represented by Portland immigration attorney, Gerald H. Robinson Esq. United States District Court Judge James Redden ruled that "Congress intended that the legal status of the petitioning business not be a dispositive consideration in immigration proceedings".

On arriving in the US in 1979, Johnson-Laird wrote the software drivers to permit the CP/M Operating System to run on an Onyx computer—this was the first commercial CP/M microcomputer with a hard disk and a data cartridge tape drive.

Johnson-Laird is one of the early pioneers in the field of digital forensics. His specialty, developed in 1987, is forensic software analysis of computer and Internet-based evidence for copyright, patent, and trade-secret litigation. He is also an expert on software reverse engineering, software development, and developing software in a clean-room environment.^{[citation needed]}

Johnson-Laird developed techniques for computerized source code analysis and the presentation of computer-based evidence that have helped to bring digital forensics into the courtroom. He has served as a Special Master to Federal District Court judges, and has served as an expert witness and provided litigation testimony in many intellectual property cases in the United States and Singapore. He also has published numerous articles on topics related to digital forensics and the legal challenges posed by emerging technologies.^{[citation needed]}