The Dragons will host arch rivals the Cardiff Blues on Boxing Day while the Ospreys will face the Scarlets at the Liberty Stadium later on that evening.
Additionally, two postponed fixtures from Rounds 4 and Round 6 have been rescheduled for the first weekend in December – Connacht v Benetton Rugby and Glasgow Warriors v Dragons.
Both games will be live on Premier Sport while S4C will also have coverage of the Dragons v Cardiff Blues.
The new year will begin with a bang as the Scarlets welcome the Dragons to Llanelli and the Cardiff Blues clash with the Ospreys in Swansea with both games being played on January 1.
Meanwhile, the Dragons will host Wasps on December 12 in their first Heineken Champions Cup clash in a decade. On the same Saturday the Scarlets will begin their Champions Cup campaign with a mouthwatering trip to Bath.
In the Challenge Cup the Cardiff Blues open their account at Kingston Park against Newcastle Falcons, while Ospreys host Castres the following day.
The Champions Cup consists of two pools of 12 clubs with the pool stage played over four rounds. The four highest-ranked clubs in each pool will qualify for the quarter-finals, which will be played over two legs on a home and away basis.
The next ranked eight clubs will qualify for the Challenge Cup last 16.
Fourteen clubs will compete over four rounds in the preliminary stage of the Challenge Cup with the eight highest-ranked clubs, as well as eight Champions Cup clubs, qualifying for the last 16.
Both finals will be played in Marseille, France, next May.
Guinness PRO12 Derby fixtures
Round 9 – Sat, Dec 26: Ospreys v Scarlets (5.15pm, Premier Sports; Liberty Stadium)
Round 10 – Fri, Jan 1: Scarlets v Dragons (5.15pm, S4C, Premier Sports; Parc y Scarlets)
Round 11 – Sat, Jan 9: Cardiff Blues v Scarlets (3pm, Premier Sports; Cardiff Arms Park).
