Has there ever been a 12–1 in all competitions?

Yes, 3 times.

The first time: June 11, 1905, Reformer beat Barracas Athletic (Barracas Athletic 1–12 Reformer) · Primera Argentina.

The last time: May 22, 1972, Ajax beat Vitesse (Ajax 12–1 Vitesse) · Eredivisie, 54 years ago.

Home wins: 2. Away wins: 1.

Nearby scores

1. 13–0 1 time
2. 13–1 1 time
3. 13–2 Never
4. 12–0 7 times
5. 12–1 3 times
6. 12–2 1 time
7. 11–0 5 times
8. 11–1 6 times
9. 11–2 3 times

All games

1. May 22, 1972 Ajax 12–1 Vitesse · Eredivisie
2. February 8, 1931 Athletic Bilbao 12–1 FC Barcelona · La Liga
3. June 11, 1905 Barracas Athletic 1–12 Reformer · Primera Argentina