The 2026 Six Nations Women's U21 Series is the third edition of the Six Nations Women's age-grade rugby union competition, and the first under the new U21 format.
The competition will run from 18 April to 10 May 2026, with fixtures scheduled to align with the 2026 Women's Six Nations Championship, allowing for double-header weekends.
Unlike the previous festival format used in 2024 and 2025, where all six teams competed at a single host venue over one week. The new format features home and away fixtures spread across three weekends in April and May.
Each team plays three matches, with teams playing either two home fixtures and one away, or one home fixture and two away. This structure is designed to replicate the training week and travel elements of the senior Women's Six Nations Championship.
From 2026, teams are permitted to select up to five players aged 23 or under in their squads.
Table ranking rules
Fixtures were announced in January 2026.