Tickets for the games are just £10 for adults and £5 for Under 16s and are now on sale from Parc y Scarlets ticket office (phone and web details below).
WRU Head of Rugby, Performance and Development Joe Lydon said, "It's vital that our Wales Under 20 players receive not only superb coaching and support systems in their rugby development, but their training and playing environment must also be of high standard. We now have world class training facilities at the National Centre of Excellence and we know that in Parc y Scarlets our elite, young players will have the best possible playing arena, as they progress further on the international player pathway.
"Llanelli is one of our true rugby heartlands and I'm sure rugby fans will be eager to watch some of the best young players in the northern hemisphere as they stake their claim for future honours."
Chief Executive of the Scarlets Mark Davies said: "We are delighted as the home of rugby in West Wales to be hosting the forthcoming Wales U20 Six Nations fixtures and with it the opportunity to further contribute to the development of great Welsh rugby talent - which is so close to our hearts and our philosophy as a region.
"We are grateful for this opportunity and to be working closely with the WRU on this exciting initiative which will showcase the next generation of Wales internationals and the investment that continues to be made in developing our top rugby players of the future. The Scarlets region including all our community clubs and supporters show great energy and passion in their support of the development of rugby from grassroots up - and we are all proud to play a part in supporting the mission to ensure a bright future for the game in Wales.
"Parc y Scarlets was conceived as a rugby stadium and is one of the finest of its kind in Europe in terms of its facilities and what it can offer supporters on a match-day but it is equally a top-class sports and community facility that has been home to international football fixtures as well as a variety of community activities throughout the year. We look forward to welcoming everyone here to heart and soul rugby country."
Wales Women take on England at Pandy Park on Sunday 6 February and Ireland on Sunday 13 March (both 2.30pm)
Cardiff Arms Park and The Brewery Field originally won the tender bids for this season's Under 20 and Women's Six Nations matches respectively but these venues have subsequently become unavailable and the tenders were re-opened.
This season's Wales Under 18 homes matches - Wales v France on March 6 and Wales v Scotland on April 10 (both 2.30pm) - will be played at St Helens, Swansea, while Parc Eirias, Colwyn Bay will host Welsh Schools Under 16 v Italy Under 17 on Saturday 16 April, 3pm.
Wales Under 20 Six Nations 2011 ticket info:
Wales U20 v England (Sat 5 Feb KO 6.30pm); Wales U20 v Ireland (Friday 11 March KO 7.10pm)
Venue: Parc y Scarlets
Tickets: £5 U16s, £10 adults
Phone: 0871 871 8088
Tickets are also on sale at the Scarlets ticket office.