Season 1An Irish-Canadian co-production, Vikings was developed and produced by Octagon Films and Take 5 Productions.Michael Hirst, Morgan O'Sullivan, John Weber, Sherry Marsh, Alan Gasmer, James Flynn and Sheila Hockin are credited as executive producers.The first season's budget was of US$40 million. The series began filming in July 2012 at Ashford Studios in Ireland, which at the time was a newly built facility.This location was chosen for its scenery and tax advantages.On August 16, 2012, longship scenes were filmed at Luggala, as well as on the Poulaphouca Reservoir in the Wicklow Mountains.Seventy percent of the first season was filmed outdoors.Some additional background shots were done in western Norway. Johan Renck, Ciarán Donnelly and Ken Girotti each directed three episodes. The production team included cinematographer John Bartley, costume designer Joan Bergin, production designer Tom Conroy, composer Trevor Morris and Irish choir Crux Vocal Ensemble, directed by Paul McGough.
Season 2On April 5, 2013, History renewed Vikings for a ten-episode second season. Jeff Woolnough and Kari Skogland joined Ken Girotti and Ciaran Donnelly as directors of the second season. Two new series regulars were announced on June 11, 2013: Alexander Ludwig, portraying the teenage Björn; and Linus Roache, playing King Ecbert of Wessex.The second season undergoes a jump in time, aging the young Björn (Nathan O'Toole) into an older swordsman portrayed by Ludwig. The older Björn has not seen his father, Ragnar, for "a long period of time". Lagertha remarries to a powerful jarl, a stepfather who provides harsh guidance to Björn. Edvin Endre and Anna Åström signed up for roles in the second season. Endre had the role of Erlendur, one of King Horik's sons.
Season 3Morgan O'Sullivan, Sheila Hockin, Sherry Marsh, Alan Gasmer, James Flynn, John Weber and Michael Hirst are credited as executive producers. This season was produced by Steve Wakefield and Keith Thompson; Bill Goddard and Séamus McInerney acted as co-producers. The production team for this season included casting directors Frank and Nuala Moiselle; costume designer Joan Bergin; visual effects supervisors Julian Parry and Dominic Remane; stunt action designers Franklin Henson and Richard Ryan; composer Trevor Morris; production designer Mark Geraghty; editors Aaron Marshall for the first, third, fifth, seventh and ninth episodes and Tad Seaborn for the second, fourth, sixth, eighth and tenth episodes; and cinematographer PJ Dillon.
Season 4Michael Hirst announced plans for the fourth season before the third season had begun airing. The fourth season began production in Ireland around the Dublin and Wicklow areas in April 2015.Additional location photography featuring Ludwig took place in Canada. Finnish actors Peter Franzén and Jasper Pääkkönen, as well as Canadian actress Dianne Doan, joined the cast of the fourth season. Franzén played Norwegian King Harald Finehair, a potential rival to Ragnar. Pääkkönen was cast as Halfdan the Black, Finehair's brother. Doan portrays Yidu, a Chinese character who has a major role in the first half of the fourth season.
Season 5At the same time that the series was renewed for a fifth season, it was announced that Irish actor Jonathan Rhys Meyers would be joining the cast,as Heahmund, a "warrior bishop". Vikings’ creator Michael Hirst, explained: "I was looking at the history books, and I came across these warrior bishops. The antecedents of the Knights Templar: these are people who were absolutely religious, yet they put on armor and they fought. Don't let their priestly status fool you, either. 'They were crazy! They believed totally in Christianity and the message, and yet, on the battlefield, they were totally berserk. WWE wrestler Adam Copeland was cast in a recurring role for the fifth season as Kjetill Flatnose, a violent and bold warrior. He is chosen by Floki to lead an expedition to Iceland to set up a colony. Irish actor Darren Cahill plays the role of Æthelred of Wessex in the fifth season. Nigerian actor Stanley Aguzie told local media he had landed a small role in the fifth season.The fifth season also features Irish actor, musician and real-life police detective, Kieran O'Reilly, who plays the role of "White Hair".In April 2017 it was announced that Danish actor Erik Madsen would join the cast for the fifth season, as King Hemmig.He spent several months of 2016 on the set of The Last Kingdom, portraying a Viking. Season 5 involved location shooting in Iceland as well as Morocco, the latter standing in for Sicily and Egypt.
Season 6Russian actor Danila Kozlovsky joined the series for the sixth season, as Oleg of Novgorod, the 10th century Varangian (east European Vikings) ruler of the Rus people. Katheryn Winnick, who portrays Lagertha in the series, directed an episode of the season. Music for the series was contributed by Scandinavian artists with strong Nordic folk influences, including Wardruna and Danheim.