Together with his clients Leo defines their IP strategy and where appropriate files, prosecutes and defends their IP rights worldwide. This also includes challenging third party rights, licensing and FTO studies.  Leo has a wide experience in patent cases before the court in The Hague and before the EPO.

Leo is actively involved in the training of new patent attorneys in Dutch, European and international patent practice. Furthermore he is an active member (chair) of the IP enforcement and Litigation group of FICPI, the International Federation of Intellectual Property Attorneys.

In his capacity as European Patent Litigator, Leo is allowed to act as UPC representative.

Since April 2026, Leo has been associated with V.O. as an of-counsel.

Working experience

• Patent Attorney, V.O. (1992-April 2026)
• Freelance consultant in Ergonomics and product design (1989-1992)
• Ergonomics Department, Volvo Cars (1989)

Education

• MSc in Industrial Design Engineering, Delft University of Technology (1989)

Directories

• “Leo Jessen … specialises in consumer products and medical devices and is adept at coordinating multi-jurisdictional strategies to strengthen European patent positions, including handling complex EPO oppositions” (IAM Patent 1000, 2026)
• “… Leo Jessen is a robust defender of his international clients’ IP rights, leveraging his mastery of Dutch and EU IP law to present cases before The Hague and the EPO with great finesse” (IAM Patent 1000, 2025)
• “Leo Jessen is the go-to mastermind of cases on consumer products, ergonomics and medical appliances. He has also been entrusted with roles of seniority, acting as chair of the IP enforcement and litigation group of the International Federation of Intellectual Property Attorneys” (IAM Patent 1000, 2024)
• Recommended individual (JUVE Patent 2020, 2021, 2022, 2023, 2024)
• “Jessen combines his exceptional technical knowledge with a fine-grained understanding of patent law to devise strategies and enhance the commercial potential of patent portfolios” (IAM Patent 1000, 2023)
• “Leo Jessen is the man to call for no-stone-unturned freedom-to-operate analyses and futureproofed protection strategies. A hugely experienced patent attorney, he plays a valuable mentoring role and is respected in the wider market as an excellent educator” (IAM Patent 1000, 2021)
• Recognized as IP Star (2015, 2014, 2017 – 2025) by Managing Intellectual Property
• Recommended Individual (IAM Patent 1000, 2020 – 2026)
• “Always performs excellently in the courtroom” (JUVE Patent 2020)
• “Gifted in both prosecution and litigation”, Leo Jessen is “extremely good at building a case” (IAM Patent 1000, 2019)
• “Peers praise Leo Jessen as a really excellent, strong attorney who’s been around for many years. Jessen prosecutes applications for a wide segment of devotees, who depend on his aptitude in filing, oppositions and appeals to keep their stress levels low throughout the patent lifecycle” (IAM Patent 1000, 2018)
• “Heineken is one of the big names that engage Leo Jessen for his drafting and prosecution talents” (IAM Patent 1000, 2017)
• “A key reference for companies in the consumer products sector, Leo Jessen has recently been advising Heineken on the expansion of its patent portfolio” (IAM Patent 1000, 2016)
• “Leo Jessen is one of a rare breed, having spent his entire career at a single firm. With V.O. since 1992, the quick-witted strategist advises mechanical engineering clients on how to procure, defend and monetise IP rights” (IAM Patent 1000, 2015)
• “Leo Jessen can address the myriad of concerns which arise in the mechanical engineering space” (IAM Patent 1000, 2014)
• “Excellent communicator Leo Jessen and Bernard Ledeboer are the top mechanical engineering specialists there” (IAM Patent 1000, 2013)
• “Leo Jessen is renowned for his creative approach, especially in relation to mechanical patents. Mechanical engineering is his field and he has profound knowledge of consumer products, ergonomics and medical appliances” (IAM Patent 1000, 2012)

Professional & Community Activities

• FICPI: Secretary of the Netherlands section and member of CET Group 7, IP Enforcement and Alternate Dispute Resolution
• AIPPI
• AIPLA

Languages

• English
• Dutch
• German
• French