Kio Gwilliam

  • Senior Associate
  • London
he / him / his
  • kgwilliam@hausfeld.com
  • +44 20 7665 5036
  • https://www.linkedin.com/in/kio-gwilliam-b9b47982/
Kio Gwilliam

OVERVIEW

Kio specialises in competition litigation, data protection claims and commercial disputes. He was promoted to Senior Associate in January 2022.

Expertise

In addition to representing clients in large scale abuse of dominance disputes against Big Tech corporations, Kio is currently part of the legal team advising Justin Gutmann in his competition collective claim against various train operators for abuses of their dominant positions, the UK’s first standalone competition collective claim of its kind.

In addition to various commercial and pro bono matters, Kio was part of the legal team acting for over 100 claimants in the Air Cargo litigation against British Airways in the High Court and Court of Appeal.

Prior to joining Hausfeld, Kio trained at Berwin Leighton Paisner LLP. 

Clients

Kio has experience representing clients on a range of antitrust, competition and data protection issues across a variety of sectors, including technology, utilities and transport. 

EDUCATION

MA in International Peace and Security, King’s College, London
LLB (Hons) in Law, The University of Sussex
LLM in Professional Legal Practice, The University of Law 

BAR ADMISSIONS

Solicitor, England and Wales, 2017

NEWS

Kio Gwilliam recognised in The Lawyer’s Top 20 cases: the associates to know

  • Antitrust et Concurrence
  • United Kingdom
  • mars 03 2025

Hausfeld features prominently in The Lawyer's 'Top 20 Litigation' and 'Top 10 Appeals' for 2025

  • Antitrust et Concurrence
  • Contentieux Commercial et Financiers
  • United Kingdom
  • janv. 13 2025

Trial in £1.5bn+ Collective Proceedings against Apple over App Store practices commences in January 2025

  • Antitrust et Concurrence
  • United Kingdom
  • déc. 20 2024

Legal 500 UK 2025 recognises 28 Hausfeld lawyers across 7 practice areas

  • Antitrust et Concurrence
  • Contentieux Commercial et Financiers
  • Responsabilité du Fait des Produits et de l'Environnement
  • Droits de l'Homme
  • United Kingdom
  • oct. 03 2024

First complaint to the ICO filed against YouTube under the Children’s Code

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • mars 01 2023

In the 2nd on-the-spot certification, the CAT authorises Liz Coll as class representative against Google

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • juil. 18 2022

A green light for the Kent collective claim against Apple

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • juil. 01 2022

CAT certifies Dr Kent's opt-out collective claim against Apple on the spot

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • mai 11 2022

Hausfeld announces seven senior promotions globally

  • Antitrust et Concurrence
  • Contentieux Commercial et Financiers
  • Responsabilité du Fait des Produits et de l'Environnement
  • Droits de l'Homme
  • Technologie & Protection des Données à Caractere Personnel
  • United States, France, Germany, United Kingdom, Netherlands, Sweden, Belgium
  • janv. 05 2022

General Court dismisses Google’s appeal of the Google Shopping Decision

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • Germany, United Kingdom
  • nov. 10 2021

The Lawyer Awards 2021 commends Hausfeld

  • Antitrust et Concurrence
  • Responsabilité du Fait des Produits et de l'Environnement
  • United Kingdom
  • nov. 02 2021

Hausfeld has responded to the Competition and Markets Authority’s invitation to comment on its proposed mobile ecosystems market study

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • août 02 2021

Google sued for excessive and unlawful charges on its Google Play Store

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • juil. 29 2021

Apple faces legal demand to repay 20 million UK customers related to excessive and unlawful App Store charges

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • mai 11 2021

The Lawyer Awards 2020 shortlist Hausfeld in the Competition & Regulatory Team of the Year category

  • Antitrust et Concurrence
  • United Kingdom
  • sept. 24 2020

High Court allows Foundem’s expert access to Google confidential information

  • Antitrust et Concurrence
  • United Kingdom
  • mars 19 2020

Google’s appeal in EU Court watched closely by digital economy

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • Germany, United Kingdom
  • févr. 13 2020

UK’s first standalone collective claim filed by Hausfeld on behalf of rail passengers

  • Antitrust et Concurrence
  • United Kingdom
  • févr. 28 2019

Four Hausfeld clients granted permission to intervene in EC's Google Search (Shopping) decision appeal

  • Antitrust et Concurrence
  • France, Germany, United Kingdom, Netherlands, Belgium
  • janv. 24 2019

EVENTS

SCL’s Tech Law Essentials Programme - Module one

  • Technologie & Protection des Données à Caractere Personnel
  • Antitrust et Concurrence
  • London 

  • 08 mars 2023

Online safety, digital services and competition in digital markets – SCL

  • Technologie & Protection des Données à Caractere Personnel
  • Online
  • 12 mai 2022

Let’s Get Digital: CMA’s Market Study in Review - Lexology webinar

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • ONLINE

  • 10 nov. 2020

ABA's 2019 Global Private Litigation Conference

  • Antitrust et Concurrence
  • Berlin

  • 17 juin 2019

PUBLICATIONS

CMA’s market study on mobile ecosystems: Setting the tone for enforcement in mobile markets

  • Antitrust et Concurrence
  • United Kingdom
  • févr. 28 2022

The Digital Services Act: What are the key provisions, and does it strike the right balance?

  • Antitrust et Concurrence
  • United Kingdom, Germany
  • mai 25 2021

The Digital Markets Act: radical reform or conservative compromise?

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • févr. 25 2021

Festina lente (make haste, slowly): the CMA takes steps towards regulating online platforms

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • août 18 2020

Confidentiality issues in UK competition disputes: guidance from the High Court

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • mai 20 2020

The CMA's interim report on online platforms and digital advertising

  • Antitrust et Concurrence
  • United Kingdom
  • mars 03 2020

PERSPECTIVES

UK Digital Markets Competition Regime now in force

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • déc. 16 2024

European Commission immediately hits Big Tech with investigations for DMA non-compliance

  • Antitrust et Concurrence
  • United Kingdom
  • avr. 05 2024

The Competition Cast - Key competition developments in the UK

  • Antitrust et Concurrence
  • United Kingdom
  • mars 15 2024

Apple and Google lose early bids to view sensitive funding information in separate collective actions

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • févr. 14 2022

German Federal Cartel Office subjects Google as ‘undertaking of paramount significance for competition across markets’ to stricter antitrust law obligations

  • Antitrust et Concurrence
  • Germany
  • janv. 07 2022

The Collective Cast - Collective proceedings against Google re UK PlayStore

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • oct. 11 2021

The Age Appropriate Design Code: Strong on principles but will it trigger change?

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • sept. 22 2021

Unlocking competition in digital markets: report and recommendations from the DMT

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • janv. 15 2021

EU digital markets legislation - the latest developments

  • Technologie & Protection des Données à Caractere Personnel
  • Antitrust et Concurrence
  • United Kingdom
  • déc. 17 2020

Conclusions from the CMA’s market study into online platforms and digital advertising: Google and Facebook’s respective market dominance is causing harm

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • juil. 03 2020

COVID-19 - CMA warns: no “free pass” for fee-paying schools to fix prices during CV-19 crisis

  • Antitrust et Concurrence
  • United Kingdom
  • mai 05 2020

Stakeholders weigh in on the CMA’s Interim Report on online platforms and digital advertising

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • avr. 22 2020

A welcome step forward for claimants fighting the confidentiality claims of "big tech" in English courts

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • avr. 06 2020

Competition litigation in the UK – 2018 in review

  • Antitrust et Concurrence
  • United Kingdom
  • déc. 27 2018

WHAT OTHERS SAY

Legal 500 UK

Kio Gwilliam has been recognised as a key lawyer for his expertise in Competition Litigation and Group Litigation Claimant by Legal 500, 2025.

Experience

Antitrust/Competition

Kio played a key role as part of the legal teams dealing with ground breaking claims as follows:

  • An opt-out collective action filed with the CAT on behalf of an estimated 19.5 million eligible UK users of smartphones and tablets running on Google’s Android operating system relating to excessive and unlawful charges on purchase in the Google Play App Store. The claim alleges that Google unfairly restricts consumers from accessing potential competition from other app distributors, by requiring smartphone manufacturers to pre-install a bundle of Google’s proprietary apps and services including the Google Play Store as well as imposing other contractual and technical restrictions
  • A representative collective action with the CAT on behalf of some 19.6 million eligible UK iPhone and iPad users relating to excessive and unlawful charges by the Apple App Store. The claim alleges that Apple’s conduct violates section 18 of the UK Competition Act 1998 and Article 102 of the Treaty on the Functioning of the European Union
  • Air Cargo, a landmark competition follow on damages claim in which Hausfeld pursued claims for losses that occurred in over 50 different jurisdictions as a result of the Air Cargo Cartel, ultimately representing 500 claimant entities - including a significant number of multinationals - against British Airways plc, and 13 Part 20 Defendant Airlines in some of the longest running, most high-profile and complex competition damages actions brought to date in the English Courts.
  • Google Shopping - Kio is part of the team representing Foundem in its claim before the High Court against Google, for abuse of its dominant position in respect of its conduct in comparison shopping. In addition, Hausfeld obtained permission to intervene in Google’s ongoing appeal of the European Commission’s June 2017 Google Search (Shopping) Decision for four Hausfeld clients, Infederation Ltd (Foundem), German press publishers’ associations VDZ and BDZV as well as Visual Meta GmbH. 
  • Trains - The very first collective claim filed by Hausfeld back in February 2019, with co-counsel Charles Lyndon. It was also the first collective claim brought before the CAT on a standalone basis. Crucially for the regime more generally, in July 2022 the Court of Appeal held in Trains that liability can be determined on an aggregate basis in collective proceedings, which was a very important ruling for collective proceedings in the UK. We helped progress the case over 5 years during which the claim benefited from our competition litigation expertise.

Technology & Data Breach

Kio played a key role as part of the legal team which: 

  • Filed a CPR 19.6 representative action brought on behalf of Duncan McCann, on behalf of up to 5 million British children aged under 13 and their parents in the High Court – alleging that YouTube’s methods of targeting underage audiences and harvesting their data constitute major violations of the UK Data Protection Act and the EU’s General Data Protection Regulation (GDPR), both of which were designed to protect citizens’ privacy rights.

What I think

UK Digital Markets Competition Regime now in force

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • déc. 16 2024

European Commission immediately hits Big Tech with investigations for DMA non-compliance

  • Antitrust et Concurrence
  • United Kingdom
  • avr. 05 2024

The Competition Cast - Key competition developments in the UK

  • Antitrust et Concurrence
  • United Kingdom
  • mars 15 2024

Apple and Google lose early bids to view sensitive funding information in separate collective actions

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • févr. 14 2022

German Federal Cartel Office subjects Google as ‘undertaking of paramount significance for competition across markets’ to stricter antitrust law obligations

  • Antitrust et Concurrence
  • Germany
  • janv. 07 2022

The Collective Cast - Collective proceedings against Google re UK PlayStore

  • Antitrust et Concurrence
  • Technologie & Protection des Données à Caractere Personnel
  • United Kingdom
  • oct. 11 2021