Defending champions, Barcelona had to qualify the hard way, after they lost 2-0 to Sevilla in the first leg of the quarter final.
The second leg saw the return of Lionel Messi — who scored the last goal as Barça thrashed Sevilla 6-1 to advance.
A Karim Benzema inspired Real Madrid had an easier route, as they consolidated on a 4-2 first leg thumping of Girona at the Santiago Bernabeu stadium, by beating them 3-1 in the return leg.
The red hot striker scored a total of three goals to help Los Blancos see off Girona in the two-legged fixture.
The first leg which is to be played at the Nou Camp, will be handled by Senior Laliga referee, Mateu Lahoz. It will be the first time in 5 years, both giants will be meeting in Copa Del Rey.
They last met in the 2014 final, when Gareth Bale famously helped Los Blancos get the better of the defending champions.
Valencia and Real Betis completes the other half of the Semifinal. Both teams will be happy to have avoided the two spanish giants.
They are billed to play first, on the 7th of February. Return legs of the two Semi finals is slated for 25th of February.