Sunday held academic positions between 1996 and 2001 at the Botswana Institute of Administration and Commerce; at what was previously known as Technikon Natal in Pietermaritzburg; the University of Natal in Pietermaritzburg; and at Vista University. Sunday has worked in policy formulation, legal advisory services, legislative drafting and management positions for over thirteen years in the land sector (Department of Land Affairs/Rural Development and Land Reform). He rendered legal opinions, appeared before parliamentary committees and drafted several articles of legislation and draft bills, specifically in land, housing, and infrastructure development. He held a principal position in developing the South African Spatial Planning and Land Use Legislation (SPLUMA) between 2001 and 2014.
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Since 2015, Advocate Sunday Ogunronbi has been briefed on a scope of matters, including general litigation in constitutional law, property law, land tenure, property rates, and planning law, amongst other cases. He has also been involved in matters such as the constitutionality of section 118(3) of the Municipal Systems Act  32 of 2000, and several land restitution cases before the Constitutional and High Courts.

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