Ryanair will offer flights to Faro in Portugal from Cardiff next summer.
The airline already offers a weekly flight from Cardiff to Tenerife in the summer.
It expects to carry 43,000 passengers from the Welsh airport.
Cardiff airport chairman Roger Lewis said: "It is fantastic to see Ryanair increase its routes and flights at Cardiff Airport. Our customers now have even more choice to travel to what is an extremely popular destination.
"Ryanair is responding to the demands of Welsh passengers by adding another essential route to its network. It is vital that our customers are offered a wide variety of choice when it comes holiday destinations."
