The Organisation of Eastern Caribbean States marked its 45th anniversary on Wednesday, celebrating more than four decades of regional integration under the theme, “One Vision, One Voice: Navigating Challenges, Shaping Our Future.”

The milestone commemorates the signing of the Treaty of Basseterre on June 18, 1981, which formally established the OECS as the successor to the West Indies Associated States Council of Ministers. Since then, the organization has expanded its membership and deepened cooperation among Eastern Caribbean nations in areas including economic development, education, health, security, environmental sustainability and foreign policy.

In a statement marking the occasion, the OECS said the anniversary serves as an opportunity to reflect on the achievements made through regional unity while reaffirming a commitment to addressing future challenges collectively.

“For 45 years, the OECS has championed regional integration, strengthening the bonds that unite our Member States and advancing a shared vision for a resilient and prosperous future,” the organization said.

The anniversary is being observed under the theme “One Vision, One Voice: Navigating Challenges, Shaping Our Future,” highlighting the importance of solidarity as member states confront economic uncertainty, climate change, natural disasters and other regional challenges.

The OECS traced its evolution through several major milestones, including the signing of the Revised Treaty of Basseterre in June 2010 and its entry into force on January 21, 2011. The revised treaty established the OECS Economic Union and strengthened cooperation among participating member states.

The organization has also expanded beyond its original membership. Martinique joined the OECS in February 2015, followed by Guadeloupe in March 2019 and Saint Martin in March 2025.

Officials said these additions demonstrate the growing appeal of regional collaboration and the benefits of collective action across the Eastern Caribbean.

As part of the anniversary celebrations, the OECS is encouraging residents across member states to participate in activities and share photographs featuring the organization’s colors of yellow, white, green and navy blue. A public fun walk is also planned in Antigua and Barbuda as part of the commemorative events.

The OECS said the anniversary is not only a celebration of past achievements but also a call to continue building a stronger and more resilient region through cooperation, shared purpose and collective action.