Dennis David Crouch (born April 30, 1975  in Columbia, South Carolina) is an American patent attorney who worked for McDonnell Boehnen Hulbert & Berghoff LLP (MBHB) in Chicago, Illinois, until 2007. In 2007, he accepted a post of associate professor at the University of Missouri School of Law in Columbia, Missouri.
In 1997, he received his B.S.E. in Mechanical and Aerospace Engineering from Princeton University, where he also earned a certificate in engineering management systems. In 2003, he received his J.D. from the University of Chicago Law School, and passed the Illinois bar examination and was admitted to practice in Illinois in the same year. He also passed the USPTO registration examination, most likely in 2003, and was registered to practice as a patent agent in February 2004 and as a patent attorney in August 2004. He runs the "Patently-O Patent Blog", a patent law blog that features analysis on current Federal Circuit law and other subjects. According to BusinessWeek, as of 2008 the Patently-O blog was the most widely read patent law blog and was included in the American Bar Association Journal blog's inaugural patent blog "hall of fame" in 2012. Crouch is reported to be "fairly obsessive about timeliness, checking the Federal Circuit's site when it is updated each morning and immediately noting new cases on his blog." 
- "Lawyer Search: Attorney's Registration and Public Disciplinary Record for Dennis David Crouch". Attorney Registration & Disciplinary Commission of the Supreme Court of Illinois. 2009-04-13. Retrieved 2009-04-13.
- Alan Cohen, Associate's IP Blog Is Patently Good Publicity, Law.com, May 11, 2006
- Private Practice Lawyer Profile for Dennis D. Crouch, martindale.com[dead link]
- Dennis Crouch, Thank you MBHB, Hello Missouri!, Patently-O: Patent Law Blog, May 8, 2007.
- "Registered Attorney/Agent Search: Dennis D. Crouch". Office of Enrollment and Discipline, United States Patent and Trademark Office. Retrieved 2009-07-13.
- At that time, the USPTO registration examination was only offered in April and October. The last examination before he was registered to practice before the USPTO was the October 2003 examination, for which the results were sent to examinees in December 2003. "Exam Results". Office of Enrollment and Discipline, United States Patent and Trademark Office. Archived from the original on June 21, 2008. Retrieved 2009-07-13.
- "Patently-O is short for 'patently ... obvious'". in IPKat, Friday fling, 3 April 2009. Consulted on April 3, 2009.
- Michael Orey, Busting a Rogue Blogger, BusinessWeek, March 27, 2008. Consulted on April 4, 2008.
- ABA Journal blog. Dec 1, 2012. Introducing Our Inaugural Blawg 100 Hall of Fame