Seán O’Donnell
Byrne Wallace Shields LLPLK Shields Solicitors LLP and Byrne Wallace LLP merged at the beginning of 2025 to form Byrne Wallace Shields LLP, with the newly formed team offering experience across the spectrum of privacy and data protection matters. The team provides ‘comprehensive’ advice, with a cross-departmental bench of specialists covering the complete data protection compliance lifecycle, from pre-incident advice, to legislative and regulatory compliance and data breach response. Overseeing the team, Seán O’Donnell focuses on data security and cybersecurity breaches, regulatory investigations, and infringement claims. Zelda Deasy’s practice centres on general data protection work, drafting, reviewing and negotiating data transfer agreements as well as online terms and conditions, data protection policies and privacy and cookies policies. Jane O’Grady has in-depth knowledge of privacy issues in the healthcare and financial services sectors and regularly advises on data protection and cybersecurity aspects of large-scale IT projects.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
‘Seán O'Donnell, Mona Costelloe and Robert McDermott are excellent litigators who are working on some of the most important and exciting data protection law cases. Their expertise in respect of the latest GDPR knowledge is unparalleled. They are a pleasure to work with; always helpful, highly efficient and friendly.’
‘Seán O'Donnell and Robert McDermott have been very hands on regarding any legal matters we have engaged them with. Very responsive and obliging in responding to queries surrounding their briefs!’
‘We first engaged with Byrne Wallace for advice on GDPR as we use a development and support partner group that are based outside of the EEA. Based on how well we were looked after, they were also engaged to assist us with more general legal advice on commercial contracts. Their advice was extremely clear and detailed.’
‘Our advisor is Zelda Deasy, who makes the whole GDPR minefield much easier to negotiate. She is clearly an expert in her field, which became more obvious when we were dealing with our clients' own GDPR representatives, both internal and external. They clearly learned a lot from Zelda!! ’
‘Seán O'Donnell is excellent. He is extremely knowledgeable and always obliging. He uses his skill and expertise to make me feel comfortable whenever we discuss complex matters that I may not understand fully.’
‘The team at Byrne Wallace Shields are professional and personable. They are easy to communicate with and are happy to negotiate and improve our position. Zelda Deasy has steered us through many regulatory changes over the years and I trust her implicitly.’
‘Zelda Deasy has exceptional attention to detail, swiftness in response and thorough subject matter knowledge.’
‘Jane O'Grady and her team are very responsive. They reply quickly and are meticulous in their attention to detail. The quality of output is top drawer, which means we can have 100% confidence in implementing/acting on the advice of Byrne Wallace Shields.’
Key clients
- Arkema S.A.
- Aserve Investigators Limited
- Axon Evolution Limited
- Circol ELT
- Cloudware Limited t/a Aladdin Schools
- DKV Euro Service Gmbh + Co. KG
- Eastpoint Enterprise Information Solutions Limited
- Environmental Protection Agency
- Horse Racing Ireland
- Local Government Operational Procurement Centre
- Marine Institute
- Neuromod Devices Limited
- NRG Panel
- OneProjects Design Innovation Limited
- PAM Occupational Health Solutions Limited
- Pelco Limited
- Phibro Animal Health Limited
- Phonovation Limited
- Results CX UK Limited
- Select Technology Sales and Distribution Limited
- ServiceNow Ireland Limited
- Tourism Ireland CLG
- Tympany Medical Limited
- ValitaCell Limited
- Zahra Media Group
- Greatech Integration
- Maître LLC
- MCCP
- FleetCor Technologies Inc
Work highlights
- Advised ServiceNow Ireland Limited on data protection compliance requirements.
- Advised the environmental protection agency on its compliance with data protection law, data protection agreements, transfers outside the EEA, engagement and sharing data with third parties and general ad hoc data protection queries.
- Advised Select Technology Sales & Distribution Limited on the data protection aspects of the acquisition of D.I.D. Electrical.
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Seán O’Donnell