She started her banking career at Prime Merchant Bank Treasury & Money Markets Group in 1991 and then joined
Ecobank Nigeria between 1994 and 2005 as a Relationship manager. In January 2005, Oni joined Standard Chartered Bank Nigeria as a Senior Account Relationship Manager where she rose to become the head of local corporates in 2010 and in 2014 was appointed as the Managing Director & Country Head of their Commercial Banking unit in West Africa. She was also appointed as the first female managing director and chief executive officer at Standard Chartered Bank in Sierra Leone in January 2021 and in January 2024 was appointed as the managing director of Union Bank. Oni is an associate member of
WIMBIZ (Women in Management, Business, and Public Sector) and honorary member of the
Chartered Institute of Bankers of Nigeria and
Nigerian British Chamber of Commerce (NBCC). ==References==