One visitor arrived as early as 6.51am at the Maes in Llantwd ahead of the gates opening at 8am.
Betsan Moses, chief executive officer of the National Eisteddfod, said: “I believe we have broken the record of the earliest person knocking on the door to enter the Maes.
“Some say that they have been part of the preparations for the last two years and wanted to be here at the start.”
Among the attendees were Super Furry Animals fans, as well as regular Eisteddfodgoers and residents who supported fundraising efforts.
Ms Moses said: “The Super Furry Animals were here later and many had come especially to see them and to enjoy them.
“A number of them, perhaps not in our traditional audience, had come early and enjoyed the day’s entertainment and were amazed at what the Eisteddfod was and I hope many of them will come back during the week.
“People from America and London were among them and that was always nice and gave us an idea of how many people travel here from afar.”
Landsker Singers from Haverfordwest were one of 14 choirs, made up of 800 singers, for the choir competition.
Founded in 1990 by Edmund Walters and Shirley Williams – the choir mainly includes members of the farming community along the Landsker line.
Last year the choir celebrated its 35th anniversary with a major concert at St David’s Cathedral over the St David’s Day weekend.
The competition was the second of the opening weekend to feature a large number of choirs, after ten choirs took part in a competition on Saturday organised by Cymdeithas Eisteddfod Cymru.
All the choirs had competed at least in two of the dozens of smaller Eisteddfodau staged across Wales each year.
The competition was won by Côr Bryn Owain from Cowbridge with Cor Godre’r Garth, Cardiff second and Côr y Gleision, Cardiff placed third.
