Holstein Kiel is the product of the merger of the predecessor teams Kieler Fussball-Verein von 1900 and Kieler Fussball-Club Holstein.
The earliest of these two teams was the Kieler Fußball-Verein, founded on 7 October 1900 from members of the gymnastics club Kieler Männerturnvereins von 1844. The club was not very successful and never played a major role in football in general.
The club later focused on athletics.
The Kieler Football Club Holstein was founded on 4 May 1902 and was renamed Fußball-Verein Holstein von 1902 sometime in 1908. The club quickly became competitive and reached the final of the German Championship in 1910, where they lost in extra time 0–1 to the team
"Karlsruhe FV".
.
In 1912 they won the German championship with a 2–1 semi-final victory over defending champions Viktoria 89 Berlin, followed by a 1–0 victory in the final over the previous year's champions Karlsruhe FV.
In 1914 the club renamed itself again after adding new hockey and athletics activities, becoming Sportverein Holstein von 1902.
7 June 1917 1. Kieler Fussball Verein von 1900 and Sportverein Holstein von 1902, greatly weakened by the First World War, merged to form the current club.
As is customary in Germany, the new association adopted the founding date of the old club, while borrowing the ground, uniform, colors, logo and name Holstein from SV Holstein Kiel.
During the 1920s the team regularly competed in the national play-offs and in 1926 reached the semi-finals where they were eliminated 1–3 by SpVgg Greuther Fürth.
In 1930 they made it to the final, losing 4–5 to Hertha.
The following year they reached the semi-finals, where they were eliminated 0–2 by TSV 1860 Munich.
Under the Third Reich, German football was reorganized into sixteen top divisions.
Kiel played in the Gauliga Nordmark and consistently finished in the top five, but was disappointed in the pursuit of the division title.
In 1942, the Gauliga Nordmark was divided into the Gauliga Hamburg and the Gauliga Schleswig-Holstein.
No longer in the company of Hamburger SV and other strong teams in the city, Kiel immediately won the new division title and defended it for the next two seasons until the end of World War II stopped play across the country.