The New York Red Bulls, who have never won MLS Cup, have a small chance at winning the CONCACAF Champions League. Have any clubs won their Champions League before their domestic league? I'm including tournaments with alternate names such as "European Cup" as long as they were for the top clubs. The Europa League and other secondary competitions don't count.
Off the top of my head I definitely remember Hamburg beating Juventus in the 1983 final ten days before they won the Bundesliga title on the final day of play (on goal difference). I'm sure there are many others before the custom of domestic leagues ending before the Champions League final became the norm.
That's not what I meant. I meant if a club won a Champions League who had never won their domestic league in any season by that time.
Ah! Gotcha. So I won't bother adding '65 Inter and '92 Barcelona to '83 Hamburg I had already mentioned.
Found eight instances. In 1970 Taj Tehran won the Asian Club Championship. The following year they won their first domestic league title. The club changed their name in 1978 and today are known as Esteghlal FC. Between 1971-1982 Necaxa were known as Atlético Español. In 1975 AE won the CONCACAF Champions' Cup. After reverting back to Necaxa, the club won their first ever Liga MX title in 1994-95. In 1978 Universidad de Guadalajara/Leones Negros won the CONCACAF Champions' Cup. Although they have won a couple of second division titles and the Copa México they have yet to win a MX Liga title. In 2000 Los Angeles Galaxy won the CONCACAF Champions' Cup. Two years later they won their first ever MLS Cup title. Sydney FC is an interesting case. Founded in 2004 they won the first tournament they ever entered, which was the 2005 OFC Club Championship. A year later they won the A-League title for the first time. At the same time Australian football moved from the Oceania region to the Asia region and today A-League clubs compete in the AFC Champions League. Jeonbuk Hyundai Motors won the AFC Champions League in 2006 Three years later they captured their first K-League championship. Waitakere United won the OFC Champions League in 2007. A year later they won the New Zealand Football Championship for the first time. And in 2014 Western Sydney Wanderers won the AFC Champions League, their first trophy of any kind. It remains their only tournament success to date.