Open navigation
Search
Offices – United Kingdom
Explore all Offices
Global Reach

Apart from offering expert legal consultancy for local jurisdictions, CMS partners up with you to effectively navigate the complexities of global business and legal environments.

Explore our reach
Insights – United Kingdom
Explore all insights
Search
Expertise
Insights

CMS lawyers can provide future-facing advice for your business across a variety of specialisms and industries, worldwide.

Explore topics
Offices
Global Reach

Apart from offering expert legal consultancy for local jurisdictions, CMS partners up with you to effectively navigate the complexities of global business and legal environments.

Explore our reach
Insights
About CMS
UK Pay Gap Report 2024

Learn more

Select your region

Languages
  • English
Social media

Gillian is a partner in the CMS UK employment team working with clients in various sectors across the UK, advising on both contentious employment matters and transactional work. Gillian works regularly with clients in the financial services, energy & life sciences sectors where her industry experience ensures her advice is well rounded and fit for purpose. Gillian frequently advises clients with a global footprint meaning she has strong experience of the challenges for international employers, both from a compliance and a culture perspective. An area of keen interest for Gillian is supporting on ED&I and in this space, by way of example, she has worked with employers on global diversity reviews, advised on the roll out of D&I reporting projects and supported employers on complex internal harassment complaints as well as defending discrimination claims before the Employment Tribunal.

Gillian is a regular speaker at conferences and an author for LexisNexis and XpertHR

Awards & Recognitions
01
  • Quote
    "Gillian MacLellan provides an outstanding level of support. She identifies team members to support on our matters with careful consideration, and always ensures only the best level of service is provided. Gillian has ensured we have been able to address such matters in a compliant, but business focussed way."
    Legal 500, 2025
  • Quote
    "Gillian is an outstanding employment lawyer."
    Chambers, 2025
  • Quote
    "Gillian is really strong in providing training and guidance in relation to tricky things."
    Chambers, 2025
  • Quote
    "I value her expertise, knowledge and guidance in the area of employment law. Extremely knowledgeable and client-focused, deals with disputes practically and always from a commercial point of view. "
    Legal 500, 2024

Relevant experience

  • Major retail bank in relation to Employment Tribunal claims, international projects and internal ER matters.
  • Key energy client in relation to UK HR & people matters, to include multiple restructures, internal investigations, policy & contract review, exits & settlement agreements and DEI matters.
  • Significant FS firm on Employment Tribunal claims, whistleblowing & investigations, TUPE and complex ER issues.
  • Multiple financial institutions on the people considerations arising from material outsourcings.
  • The Scottish public sector on the complex employment issues arising out of its GBP 100m+ wide area network contract with Capita and supporting through competitive bid dialogue.
  • Multiple NDPBs on HR matters, DSARs, employees disputes and TUPE.

Education

  • 2000 - Dip LP, Glasgow Graduate School of Law, Glasgow
  • 1999 - LLB (Hons), University of Glasgow, Glasgow

Gillian is a partner in the CMS UK employment team and advises on all employment law and people related matters. Much of Gillian’s practice is in financial services where she has advised banks and insurance companies throughout her 20 years as an employment lawyer, being based in each of our Edinburgh, Glasgow and London offices at different stages in her career. She is regularly involved in advising on regulatory matters such as implementation of the SMCR, application/interpretations of COCON, sensitive whistleblowing cases and advising on exits of senior regulated employees. Gillian is also active in the diversity and inclusion space which is now a red flag risk issue for all FS firms as well as a priority of the Regulators.

Awards & Recognitions
01
  • Quote
    "Gillian MacLellan provides an outstanding level of support. She identifies team members to support on our matters with careful consideration, and always ensures only the best level of service is provided. Gillian has ensured we have been able to address such matters in a compliant, but business focussed way."
    Legal 500, 2025
  • Quote
    "I value her expertise, knowledge and guidance in the area of employment law. Extremely knowledgeable and client-focused, deals with disputes practically and always from a commercial point of view. "
    Legal 500, 2024

Relevant experience

  • Leading the CMS team advising a UK retail bank on its Employment Tribunal litigation, as well as advising them on global diversity projects, international trackers, their approach to investigation of sexual harassment and complex outsourcing negotiations and drafting.
  • Advising an FS firm in relation to the departure of their CEO and subsequent dispute over the terms of the individual’s regulatory reference following challenge by the FCA.
  • Successfully defending a UK bank in recent race discrimination claim by an existing employee alleging discriminatory culture and harassment.
  • Working as part of the project team advising an FS firm in relation to highly sensitive whistleblowing allegations involving multiple grievances and multiple DSARs.
  • Advising a household name retail bank in relation to the contentious exit of the CEO of a recently acquired technology company.
  • Supporting insurance clients on the people considerations arising from material outsourcings and corporate restructures.
  • Supporting a financial services client on the TUPE aspects of a £700m datacentre/infrastructure outsourcing and the outsourcing of its HR recruitment operations.

Education

  • 2000 - Dip LP, Glasgow Graduate School of Law, Glasgow
  • 1999 - LLB (Hons), University of Glasgow, Glasgow
Back to top