SJK

SJK was formed on 5 November 2007 as a merger between the first teams of TP-Seinäjoki and Sepsi-78. It was told to the public five days later. Sepsi-78 had a board meeting on 24 October and TP-Seinäjoki on the next day. Both clubs supported the merger. Sepsi-78 and TP both gave up their place in Kakkonen. The first signing of the new club was Petri Huttu. There were several negotiations about the merger over the years. The main reason was the inadequacy of players. The clubs continued doing junior work after the merger, but could also have their own team in the lower divisions. The work name of the club was Seinäjoki Futis, and there was a contest about the official name, where everyone could suggest a name. The final name was Seinäjoen Jalkapallokerho, that had been suggested by many people. There was also a contest about the logo and uniform. The registered name of the club is Seinäjoen Jalkapallokerho ry, and it was registered on January 22, 2008. Mikko Latomäki was chosen as the first chairman. Jukka Saarijärvi was chosen as the vice chairman. Saarijärvi was a former TP-Seinäjoki chairman.

In 2013 SJK started its second season in Ykkönen. In 2012 SJK had been placed second. SJK made some signings for 2013, which included a Spanish La Masia graduate Josu and Estonian Mihkel Aksalu. SJK started the season on May 4 with a 2–1 win over PK-35 Vantaa. SJK played AC Kajaani on June 30 and won 1–7. Kajaani made a complaint to Palloliitto about the amount of foreigners in SJK. The complaint went through and AC Kajaani was changed as the winner of the match. SJK complained about the decision and the result was again changed. AC Kajaani complained again, but later canceled it. After that SJK lost five matches in a row. SJK however did win eight matches in a row after that. The promotion to Veikkausliiga was confirmed on 29 September 2013 in a homematch against FC Haka. There was a record breaking attendance (4 798). The match was a 1–1 draw.

SJK started the season 2014 with winning the League Cup. SJK won the final 2–0 against local rivals Vaasan Palloseura. The season started poorly, at the end of May the club was at the eleventh place. After that SJK won seven games in a row and those results lifted SJK to the second place. HJK won the league and SJK was second. SJK was the only club to win against HJK under Mika Lehkosuo. SJK lost only two of the last 24 games. The most important players were Mihkel Aksalu, the league's best defender Cedric Gogoua, Johannes Laaksonen and Toni Lehtinen.

For the 2015 season SJK got even stronger. There were new signings like Mehmet Hetemaj and Ariel Ngueukam. SJK was considered as the biggest challenger of HJK. SJK was at the top of the table in September. SJK won HJK 3–0 in Seinäjoki. At the end of the season SJK's biggest challenger was Rovaniemen Palloseura. SJK won the league with one point difference to RoPS. The most important players were Roope Riski and Liverpool FC loanee Allan. SJK was chosen as the team of the year in Finland's sports gala.

SJK won the Finnish Cup in 2016. It was the first time in the club's history.

SJK's head coach Simo Valakari was surprisingly sacked on February 17, 2017. He was replaced by Sixten Boström. Sixten Boström got also sacked after poor results in May and was replaced by Spanish José Manuel Roca Roca was sacked in September. SJK Akatemia coaches Brian Page and Toni Lehtinen did the job for the rest of the poor season. Under Page and Lehtinen SJK lost the Finnish Cup final to HJK. Tommi Kautonen was hired as the new head coach in October 2017. The season 2018 didn't start as planned and Kautonen was sacked. He was replaced by Aleksei Borisovich Yeryomenko. Yeryomenko could save SJK from relegation. Yeryomenko continued as the head coach in 2019. SJK signed for example Sergei Eremenko and Moshtagh Yaghoubi. SJK didn't win a single game in the group stage of the Finnish Cup in the winter. The Veikkausliiga-campaign started well, because SJK won in the first round for the first time ever. SJK won KPV in the end of April and was at the first place of the league. Despite the good start, SJK couldn't get good results. Yeryomenko was sacked in August. The replacement was Brian Page. SJK didn't win any games for the rest of the season. SJK placed ninth.

After the season SJK appointed Jani Honkavaara as the new head coach. Honkavaara signed many prolific players for the 2020 season, such as Ariel Ngueukam, Robin Sid, Tero Mäntylä and Niko Markkula. In the winter, SJK once again could not get through from the group stage of the Finnish Cup. As the Veikkausliiga season started in July, SJK won in the first round against TPS. SJK had a good start to the season, but the results started to get worse quite quickly. In the summer transfer window the club signed a couple of players, such as Jake Jervis and Emmanuel Ledesma. They proved themselves quickly and with their lead SJK could end the season somewhat brightly. SJK finished seventh, which was disappointing for the club and the supporters. In the 2021 season, Honkavaara led SJK to finish 3rd in the league and win bronze medals.

During the 2022 and 2023 seasons, the first team was managed by Joaquín Gómez. In August 2022, club's academy product Daniel Håkans was loaned out to FK Jerv in Norwegian top-tier, and later acquired by Jerv on a permanent contract.

On 6 March 2023, SJK officially announced a co-operation deal with Ghanaian football academy Vision FC, presented by the sporting director Richie Dorman. SJK and Vision had already worked together for a while before the announcement. After the 2023 season, Terry Yegbe, who had arrived to SJK from Vision, was acquired by IF Elfsborg for a reported transfer fee of €600.000–700.000.

For the 2024 Veikkausliiga season, the reserve team head coach Stevie Grieve was appointed the manager of the first team. However, due to his lack of required UEFA Pro-license, he worked first as an assistant coach to Toni Lehtinen. On 29 May 2024, he was named the manager officially, after he was earlier accepted to UEFA Pro-class.