Serena has been reported missing from her home in Magheramason.
And police believe the 15-year-old may have travelled to Derry.
It is believed she left sometime between Wednesday night and Thursday morning.
A police spokesperson said: “Serena is approx 5ft 5in height with long dark hair.
“She may be wearing white Nike trainers and dark jeans.
“Serena may frequent the Waterside area specifically Tescos and the Crescent Link retail park.
“If anyone has information on her whereabouts please contact Police on 101 quoting ref. 303 of 23/5/19.”