Ssenyonyi made the remarks while speaking as a guest during the East African Community Parliamentary Week.
He said regional integration can only succeed if it is anchored in institutions that inspire public confidence and effectively serve the people.
"Regional integration can only succeed when it is anchored in strong institutions that command the confidence of the people they serve," Ssenyonyi said.
The Opposition leader argued that the success of East African integration should be measured by the practical benefits it delivers to ordinary citizens rather than the number of agreements signed by governments.
"Regional integration, at its core, is not about treaties, protocols, or institutions. It is about whether a trader can move goods across a border without unnecessary delay, whether a young graduate can find work in another partner state without wading through endless paperwork, and whether a business or a family can look beyond their national borders and see opportunity rather than obstacles," he said.
Ssenyonyi added that for the East African Community to realise its vision, member states must strengthen institutions by making them transparent, accountable and responsive to the needs of citizens.
The East African Community Parliamentary Week has brought together legislators and other stakeholders from across the region to discuss ways of deepening regional integration, harmonising laws and advancing the East African Community agenda.