Mark Osbourne, CPA

Controller, Client Accounting & Advisory Services
(567) 833-8031

Mark joined GBQ in 2022, serving as Controller of the firm’s Client Accounting & Advisory Services team, which provides outsourced accounting and other strategic business consulting services.

Mark brings over 25 years of public accounting experience with him to GBQ. Previously, he served in local, regional and global accounting firms, providing audit and accounting services to small and mid-sized businesses in various industries, including manufacturing, distribution, service and nonprofit, with expertise in employee benefit plans, income tax accounting and lease accounting.


  • Hillsdale College – B.A., Accounting

Professional Associations

  • American Institute of Certified Public Accountants
  • The Ohio Society of Certified Public Accountants