Katie Sims will captain Cardiff in their Regional Age Grade Championship opener against Dragons RFC on Sunday (KO 11.15am).
The Blue and Blacks, who finished top of the pile in the inaugural campaign last season, will host the first round of games at Cardiff Arms Park, where Ospreys and RGC will also go head-to-head.
Sims lines up on the blindside and is joined by Riley Stanger and Manon Blackford in the back row.
The lock combination of Izabel Wing and Fern Cumine both featured for Wales U18 last summer, while the pack is completed by a front row of Crystal James, Shannell Williams and Niamh Padmore.
Outside half Rachel Thomas-Evans is another who enjoyed international experience last season, and she links up with Seren Lockwood at half back.
Nia Fajeysian, who represented Urdd in the recent World Schools 7s in New Zealand alongside Sims and Thomas-Evans, is handed the number 13 jersey, forming a midfield partnership with Sophie Southgate.
The starting line-up is completed with the back three of Madison Isgrove, Raylee Caviell and full back Rhianna Bryant.
Hartpury College back row Gwennan Hopkins, who captained club and country last season, is named on the bench.
Cardiff U18: Rhianna Bryant; Raylee Caviell, Nia Fajeyisan, Sophie Southgate, Madison Isgrove; Rachel Thomas-Evans, Seren Lockwood; Crystal James, Shannelle Williams, Niamh Padmore, Izabel Wing, Fern Cumine, Katie Sims (capt.), Riley Stanger, Manon Blackford
Replacements: Nia Powell, Tilly Vucaj, Meg Morris, Ella Fry, Gwennan Hopkins, Brooke Bevan, Sophia Foscolo, Libby Edwards
Round 1 (Cardiff Arms Park) - Sunday, 8 January
Cardiff v Dragons (11.15am)
RGC v Ospreys (12.45pm)
Round 2 (Llandovery) - Sunday, 15 January
Scarlets v Ospreys (12pm)
RGC v Dragons (2.30pm)
Round 3 (Parc Eirias) - Sunday, 29 January
Scarlets v Dragons (1pm)
RGC v Cardiff (3pm)
Round 4 (The Gnoll, Neath) - Sunday, 5 February
Ospreys v Cardiff (11am)
RGC v Scarlets (3pm)
Round 5 (Ystrad Mynach) - Sunday, 19 February
Cardiff v Scarlets (1pm)
Dragons v Ospreys (4pm)