A database administrator (DBA) plays a crucial role in an organization by managing and maintaining database systems. Their responsibilities include monitoring database performance, ensuring data security, and performing regular backups. DBAs also optimize database structure and queries, ensuring efficient data retrieval and application performance. They are essential for implementing database policies and ensuring compliance with regulations regarding data management. By maintaining the integrity and availability of databases, DBAs support business operations and decision-making processes, making them critical to an organization's success.