Methods, apparatus, and systems to perform transparent database switching using master-replica high availability setup in relational databases are disclosed. An example system includes a first virtual appliance including a first proxy and a master database, the first proxy to forward service traffic to the master database, the master database to read and/or write data based on the service traffic; a second virtual appliance including a second proxy and a first replica database, the second proxy to determine data stored in the master database, the first replica database to replicate the master database; and a third virtual appliance including a third proxy and a second replica database, the third proxy to, in response to determining the master database of the first virtual appliance is to power down, promote the second replica database to the master database.