Mikko’s practice focuses on various forms of corporate transactions, mergers and acquisitions, finance advisory, and securities regulation. He frequently provides advice regarding transactional matters, governance, and financing issues to corporations, financial sponsors, and their boards. Mikko has also advised many industrial and technology companies in equity financing and restructuring situations and has considerable experience in public takeovers, mergers and cross-border transactions, including some of the largest transactions in the Nordic market.

Mikko is a frequent speaker at university lectures and seminars. Mikko is also entrusted with non-executive board memberships in various companies and charitable organisations. He currently serves as the chairman of the Turku University Foundation and is active in Hannes Snellman’s ESG Group.

Mikko is also qualified to practice in the State of New York.

Rankings

  • Hall of Fame, Commercial, corporate and M&A, Legal 500, 2025
  • Ranked Band 1 in Corporate/M&A in Chambers Europe, 2025
  • "We use him for challenging work as he is one of the most reliable advocates on the Finnish market.", Corporate/M&A, Chambers Global, 2025
  • Recommended by clients and peers, Who’s Who Legal: M&A and Governance, 2024
  • Recognised as a Market Leader in the practice areas of Capital Markets: Equity and M&A and the industry sectors of Industrials and Manufacturing and Technology and Telecommunications, IFLR1000, 2024
  • Hall of Fame, Commercial, corporate and M&A, Legal 500, 2024
  • Ranked in Corporate/M&A in Chambers Europe, 2024
  • “Mikko Heinonen is a very experienced partner with the ability to make decisions on tough questions and guide customers.” Chambers Global, 2024
  • "Very good legal knowledge, seniority, strong negotiation skills, strong project management, strong communication. Extremely broad knowledge. On my speed dial and my go-to external lawyer. He is a brilliant attorney that every company should have onboard during a public tender offer. Precise and accurate advice on matters with a very strategic and tactical approach.", IFLR1000, 2022
  • 'One client describes him as "a solid and experienced legal adviser."', Corporate and M&A, Chambers Global 2022
  • Hall of Fame, Commercial, corporate and M&A, Legal 500, 2022
  • Clients say: "Excellent. Deep knowledge and excellent collaboration skills.", "Professional, shows good judgement. Easy to work with. Always available.", IFLR1000, Financial and corporate, 2021
  • Ranked in Band 1 in Corporate/M&A in the 2021 edition of Chambers Global and Chambers Europe
  • "Mikko Heinonen is not only a great lawyer but also has excellent business acumen and can look at a transaction both in detail but more importantly also from a helicopter view w/o always including subject matter experts.", Commercial, corporate and M&A, Legal 500, 2020
  • "Mikko Heinonen – excellent overall commercial and governance advice.", Commercial, corporate and M&A, Legal 500, 2020
  • 'Clients hail Mikko Heinonen as "one of the best lawyers in Helsinki," and endorse him for being "extremely knowledgeable." He receives further praise for being "very pragmatic, a good thinker and getting things done efficiently."', Corporate and M&A, Chambers Global and Chambers Europe 2020
  • Ranked in Band 1 in Corporate/M&A in the 2019 & 2020 editions of Chambers Global and Chambers Europe
  • Mikko is ranked as a Market leader in Capital Markets and M&A in the 2019-2021 editions of IFLR1000
  • "Clients enthuse that 'he is very analytical.' Another source adds that 'he is well connected and aware of developments in the local market.'", Corporate and M&A, Chambers Global 2018 and Chambers Europe 2018
  • "Managing Partner Mikko Heinonen 'is absolutely splendid; his approach to people and problems is impressive,' according to clients, who also describe him as 'client and solution-oriented.'", Corporate and M&A, Chambers Global 2017 and Chambers Europe 2017
  • Leading individual, Commercial, corporate and M&A, Legal 500, 2015-2021
  • "Mikko Heinonen is 'a top-notch, pragmatic but firm lawyer who is very nice to work with,' " Corporate and M&A, Chambers Global 2016 and Chambers Europe 2016
  • 'Clients describe managing partner Mikko Heinonen as "an excellent partner. He always keeps focused on our priorities." Other interviewees report: "We are so impressed with him. He is strategic and gives us real business advice. He is very helpful."', Capital Markets, Chambers Europe 2015
  • "... 'He is splendid – a top choice for leading transactions,' say clients. He has notable experience of public M&A mandates",  Corporate/M&A, Chambers Global 2015 and Chambers Europe 2015
  • Ranked as "Lawyer of the Year" in Venture Capital Law (Helsinki, 2015) by Best Lawyers®
  • "...Mikko Heinonen is an esteemed presence in the field, noted for his 'solution-oriented' approach to major transactions. A member of the New York Bar, he is a particularly popular choice on international matters.", Corporate/M&A, Chambers Global 2014
  • Ranked among the best lawyers in the 2012, 2013, 2014, 2015, 2016 and 2017 editions (Helsinki: Capital Markets, Corporate Governance & Compliance Practice, Corporate Law, Mergers and Acquisitions, Private Equity and Venture Capital) of Best Lawyers®
  • 'Mikko Heinonen is highly reputed amongst interviewees who describe him as hardworking and experienced', Corporate/M&A, Chambers Global 2013 and Chambers Europe 2013
  • "...‘good advice as well as the ability to manage a team while keeping to deadlines’.", Corporate and M&A, Legal 500, 2013
  • 'Peers describe him as "an excellent lawyer, with a very good approach to clients and work."', Capital Markets, Chambers Europe 2012
  • '...peers recommend Mikko Heinonen as "very knowledgeable in a large range of corporate matters."', Corporate/M&A, Chambers Global 2012
  • ’Mikko Heinonen is praised for his innovative and service-minded approach and reputed for having broad knowledge in public M&A and capital markets.’, Capital Markets and Corporate/M&A, Chambers Europe 2011
  • Ranked as a Highly regarded lawyer in Capital Markets and Corporate and M&A in the 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 and 2018 editions of IFLR1000
  • 'Mikko Heinonen is also praised by clients for his communication skills. "Mikko Heinonen is one lawyer that really stands out; I like him a lot, he is very client-orientated," says one.', IFLR1000, 2011
  • "I work with Mikko Heinonen and several other partners," says one client, "and it's always above all expectations." The client adds: "They focus on the client needs rather than just responding to questions...", '"Heinonen is easy to approach and very client-focused," says one client.', Banking, Mergers and acquisitions, IFLR 1000, 2010
  • 'Mikko Heinonen is “a highly visible and respected lawyer”...and is also described by peers as “an efficient lawyer for all corporate matters.”', Chambers Europe 2009
  • 'Mikko Heinonen is an “absolute star” regarded by one source as “one of the brightest people in the legal profession.” He “works incredibly hard for his clients” and is “highly reliable,” and clients say they “never have to worry about anything” when instructing him.', Chambers Europe 2008
  • ‘The “intelligent and reliable” Mikko Heinonen is active in a range of transactions and counts financing as a specialism.’, Corporate/M&A, Chambers Global 2008

Memberships and Positions of Trust

  • Member of the Finnish Bar Association
  • Member of the New York Bar Association
  • Member of the International Bar Association

Professional Background

  • Head of M&A 2024–
  • Partner, Hannes Snellman, 2003–
  • Senior Partner, Hannes Snellman, 2020–2023
  • Managing Partner Helsinki, Hannes Snellman, 2011–2019
  • Head of M&A or Capital Markets, Hannes Snellman, 2005–2019
  • Associate, Hannes Snellman, 1997–2003

Education

  • LL.M., Harvard Law School, New York Bar Exam, 2002
  • Master of Laws, University of Turku, 1997