The 2026-2027 ROU1 season consists of 2 stages. In the first stage, each ROU1 team plays the other 15 ROU1 teams in Home-Away matches for a total of 30 league matches per team. The second stage consists of the Championship Round and the Relegation Round. In the Championship Round, each team plays Home-Away matches against the other five ROU1 teams for 10 additional league matches (40 total per team) to determine final rankings for the 2027-2028 UEFA Champions League and the 2027-2028 UEFA Europa Conference League placements. In the Relegation Round, each team plays one match against each of the other nine ROU1 teams for 9 additional league matches (39 total per team) to determine determine the relegation placements. Table ranking ties are broken by (1) head-to-head points, (2) head-to-head goal difference, (3) head-to-head goals scored, (4) goal difference, (5) goals scored, then (6) a playoff.

At the end of the 2026-2027 ROU1 Relegation Round, the 1st and 2nd place Relegation Round teams will play a one-legged playoff against each other. The winner plays a Home/Away highest aggregate score UEFAECL playoff against the 3rd place Championship Group team.

At the end of the 2026-2027 ROU1 Relegation Round, the 9th and 10th place Relegation Round teams are relegated to the ROU2, and the 7th and 8th place Relegation Round teams will play a Home-Away highest aggregate score playoff with the 3rd and 4th place ROU2 teams.