Seyi had worked in various high profile companies including accounting firms like Bode Ogunleye & Co. (Chartered Accountants), and Oladega Alogba & Co. (Chartered Accountants); Managing Partner, JHI-AO&A Chartered Accountants (an affiliate of JHI, USA). He was an Accountant of Lagos Chamber of Commerce & Industry; Financial Controller at Topbrass Aviation Limited; Head, Financial/Internal Control Division of Vigeo Group; General Manager, Finance of Vigilant Insurance Company Limited (now NEM Insurance Plc), Chief Financial Officer and later elected as Executive Director, Finance of Century Group.

He served as Director, Professional Accountancy Tutors Limited; Chairman, Accounting Technical Committee of the Nigerian Insurers Association, NIA (2002/3), and Member of both the Annual General Meeting and Publication Committees of the Chartered Institute of Taxation of Nigeria (CITN); member of four Steering Committees of the Nigerian Accounting Standard Board – NASB – now Financial Reporting Council (FRC), on Consolidated Financial Statements and Accounting for Investment in Subsidiaries; Business Combination; Investment in Associates and Interests in Joint Ventures.

He was a facilitator at ICAN MCPE Programme (2001 – 2004). In February 2012, Seyi Katola was elected a Non-Executive Director by Century Bumi Limited, a Nigerian-Malaysian company.

In 2017, Seyi was appointed the Coordinator for the newly birthed ICAN MCPE E-Learning Programme. He still facilitates for both ICAN and CITN.
Seyi currently serves as the Group Managing Director/Chief Executive of a newly established Universal Integrated Solutions & Investment Services Limited that is into the Power, Real Estates, Health, Oil & Gas and Agricultural Sectors; and Chairman, Bratim Group, Abuja.