In 1918 Fredriksskans was opened and at the same time the where a major conference in Kalmar about the high number of clubs in the town, this led to the merging of IF Gothia and Kamraterna to Kalmar Idrotts Sällskap and Kalmar IK merged with Falken to form Kalmar AIK. In 1927 Kalmar Idrotts Sällskap changed its name to Kalmar FF.
In 1927-1928 they qualified for the local league in the Swedish league system, IFK Oskarshamn won the league and was moved up to the Southswedish league, covering both Småland and Skåne, however IFK Oskarshamn renounce its position and it was given to Kalmar FF, this gave rise to complaint from the clubs in Skåne since there were no good train connections to Kalmar at that time, however SJ solved it. In their first game they defeated KIS Malmö FF with 6-0.
In 1949 the club reached Allsvenskan for the first time after defeating Halmstads BK in the decisive game of the season; during this time Swedish leagues were played autumn–spring, on 31 July they played their first game in Allsvenskan against Degerfors IF and lost 2-0, afterward, the later world famous Gunnar Nordahl claimed that he had seen much worse newcomers, also this year, on 4 September Kalmar faced Malmö FF in front of 15 093 people in the audience; this is still the audience record on Fredriksskans.
Between 1950 and 1955 the club went up and down between Allsvenskan and Division 2. In 1955 they fell down to Division 2 and stayed there for 20 years; during this time players like Hungarian Ference Marko represented the club at the same time as he lived at the refugee camp in Borgholm in 1957, in 1959 Sune "Mona-Lisa" Andersson, who won an Olympic medal in the 1948 Summer Olympics as a player, as manager, during this time Sten-Åke Johansson played for the club and became the top goalscorer for all time for the club, on 19 October 1975 Kalmar FF defeated Västra Frölunda and returned to Allsvenskan.
In 1976 the club played its 100th game in Allsvenskan against GIF Sundsvall, however this ended with 9-2 defeat and led to manager Kay Wiestål being fired. The 1977 season became the club's most successful season so far; a group of companies sponsored the club's buying of Benno Magnusson; the club was able to end in 3rd place at the end of the season, earning the club its first medal.
In 1981 the club won its first title ever, by defeating IF Elfsborg with 4-0, the club won the Svenska Cupen for the first time ever, however they failed to stay in Allsvenskan and was relegated to Division 1; however the spell was only one year long and Kalmar returned in 1983.
1985 became the club's most successful season, as the club ended up in second place behind Örgryte IS and Billy Lansdowne and Peter Karlsson both became the league's top goalscorer along with Sören Börjesson, Örgryte IS, all scoring 10 goals each. The following year did not go as good; the club was relegated from the top league and the only happiness in 1987 was when the club yet again won the Cup title, this time against GAIS, however the club fell out of Division 1 this year.
In 1988 Kalmar FF won Division 2 without a single defeat which is a record in Division 2 and higher leagues. Between 1989 and 1997 the club spent most of its time in second highest league; this caused serious economic problems for the club.
After returning to Allsvenskan in 1998, but in 1999 the club fell out again, the only good thing was that the economy had been restored and was in good shape again. During the 2000 season club had to fight to avoid relegation from the second highest league and was only able to do it in the end of the season.
The goal of the 2001 season was to return to Allsvenskan again, after buying several new players such as Lasse Johansson, Fredrik Gärdeman and Lucas Nilsson, the club was able to return to Allsvenskan again, unfortunately the club was relegated directly. During the 2002 the first Brazilian, Alysson, arrived at the club.
The two following seasons, 2005 and 2006, Kalmar ended up in 3rd and 5th respectively. Then in 2007 they made a great run from start to finish and finally ended up in second place after champions IFK Göteborg. They won Svenska Cupen the same year by beating IFK Göteborg with 3-0 at Fredriksskans in Kalmar.
Before the start, several Swedish experts believed that Kalmar FF would be one of the teams fighting for the championship title 2008, the club started the season stable and as the season went on the club performance became stronger and saw the club win many big victories, only other team able to keep up was IF Elfsborg. The club had to wait until the last match of the season against Halmstads BK in Halmstad before they could become champions. Before the final match Elfsborg was behind with 3 points and 9 goals. The match against Halmstads BK ended 2-2 placing the club 1 point ahead of Elfsborg.Patrik Ingelsten also became the league's top goalscorer of the season with 19 goals scored. The team reached the final in Svenska Cupen yet again and also this year against IFK Göteborg, however this year IFK won 5-4 on penalties after full-time and extra time had ended 0-0. The club also had the chance to reach the group stage of the UEFA Cup. After strong play against Racing FC from Luxembourg and Gent from Belgium, the club faced Dutch team Feyenoord, after winning 1-0 away in Rotterdam the club lost home with 1-2, in Borås at Borås Arena since Fredriksskans failed to reach UEFA demands, sending the club out of the competition on away goals.
A. ^ The title of "Swedish Champions" has been awarded to the winner of four different competitions over the years. Between 1896 and 1925 the title was awarded to the winner of Svenska Mästerskapet, a stand-alone cup tournament. No club were given the title between 1926 and 1930 even though the first-tier league Allsvenskan was played. In 1931 the title was reinstated and awarded to the winner of Allsvenskan. Between 1982 and 1990 a play-off in cup format was held at the end of the league season to decide the champions. After the play-off format in 1991 and 1992 the title was decided by the winner of Mästerskapsserien, an additional league after the end of Allsvenskan. Since the 1993 season the title has once again been awarded to the winner of Allsvenskan.