|Full name||Sport Klub Ljubljana|
|Ground||Stadion ob Tyrševi cesti,
Sport Klub Ljubljana (English: Ljubljana Sports Club), commonly referred to as SK Ljubljana or simply Ljubljana, was a Slovenian football club from Ljubljana. The club was founded in the mid-thirties after merging with Primorje. SK Ljubljana was dissolved in 1941, when the World War II breaks up in Yugoslavia. The club colours were black and white. Although the 1935–36 Yugoslav Championship was played in a cup format, by playing in the semi-finals SK Ljubljana was among the top 4 clubs, which is the best result ever of a Slovenian club in the Yugoslav highest level.
Soon after its formation, SK Ljubljana were the champions of the 1935–36 Ljubljana Subassociation, and as such, they got a spot in the highest national level, the Yugoslav Championship. The 1935–36 Yugoslav Championship was played in a cup format and SK Ljubljana archived the best ever result of a Slovenian club in the Yugoslav highest level, finishing among the best four. Coached by an Hungarian, Gábor Obitz, they surprised Concordia Zagreb in the 1/8 finals by beating they 3:0 both home and away, then in the quarter-finals they eliminated Krajišnik Banja Luka winning them 3:1 at home and 4:1 away. Their impressive campaign was only stopped in the semi-finals. Their opponent was BSK Belgrade who was dominating Yugoslav football in that period and was running for their third consecutive title. It was hard to expect a surprise, and BSK won both matches by 3:1 and later ended up being champions after beating Slavija Sarajevo in the final.
Next season, 1936–37, SK Ljubljana played again among the best Yugoslav clubs, however this time the league was played in a two-round robin system which will always be used since then, and the result was a modest 8th place out of 10 clubs. Their third consecutive participation in the Yugoslav elite was even worse; Ljubljana finished in 9th place out of 10 clubs. The 1938–39 season saw an expansion to 12 clubs and SK Ljubljana, playing their fourth consecutive season in the league, finished in 9th place, in front of relatively inexperienced clubs such as Građanski Skopje, Sparta Zemun and Slavija Varaždin.
The 1939–40 season saw a change in the league format. Two leagues were formed, the Serbian League and the Croato-Slovenian League. The Yugoslav champion was to be decided in a final tournament which was a league formed by the best three clubs of each of the leagues. SK Ljubljana played in the Croato-Slovenian League, however failed to qualify to the final tournament. The 1940–41 season was intended to be played in a similar system, only that the Croato-Slovenian League was separated into a Croatian and Slovenian leagues. SK Ljubljana won the 1940–41 Slovenian League thus qualifying to the final tournament to decide the Yugoslav champion, however due to the Axis invasion and the subsequent entry of the Kingdom of Yugoslavia in the World War II, the final tournament was not played.
In conclusion, SK Ljubljana was the powerhouse of the Slovenian football during its existence. It continued the tradition of AŠK Primorje in gathering most of the best Slovenian players of that time, and became a regular in the Yugoslav elite. Its first season however remained as their best one; by becoming one of the top 4 clubs in the country, they achieved the best result ever of a Slovenian club in the Yugoslav First League.