Published Wednesday, 06 August 2014
The Friends star and the Snow Patrol rocker, who announced their engagement in June, jetted into Londonderry last month so Cox could meet her fiance's family.
The couple is also believed to have visited a number of potential wedding venues, and have picked Ashford Castle in Co Mayo for the ceremony, according to The Sun.
They plan to marry there by the end of the year and follow it up with an extravagant party in Los Angeles.
A source tells the newspaper: "Johnny took Courteney to Ireland to meet his family and they fell in love with Ashford Castle.
"They want to get married at the end of the year and have a big bash in L.A. on a Malibu Beach at the end of the year."
The pair began dating last year after being introduced by a mutual friend, singer Ed Sheeran.
The reportedly moved in together in April.
This is the first marriage for McDaid and the second for Cox, who split from ex-husband, actor David Arquette, in 2010 after 11 years together.