1. Mani Ratnam’s debut movie was in Kannada. Pallavi Anu Pallavi
2. Anil Kapoor (debuted) was the hero of the Kannada movie Pallavi Anu Pallavi
3. Juhi Chawala first major hit was Premaloka 1987. IMDB comment “You have seen QSQT, u have seen DDLJ, u have seen Maine Pyar Kiya, but if you have not seen Prema Loka, then u haven’t seen the movie that started the trend which was followed by the romantic movie makers all over India. Prema Loka has a very fresh and lively look to it and considering that it was shot in 1987, it was way ahead of its time. Ravichandran as the débutant director and actor is wonderful in the movie. Juhi Chawla, who went on to act in some of the blockbuster Hindi movies,is at her pretty and bubbly best. Ravichandran has taken every minute detail into consideration. This is probably the first movie in India which truly made a fashion statement. He also imported a Honda bike, for the movie.”
4. Prithvi Raj Kapoor played role of Rajkumar’s father in the movie Sakshatkara -1971
5. Girish Kasaravalli has to his distinction four Golden Lotus Awards max for any director.
6. Raj Kumar won 9 state awards for acting but no national award. Surprisingly enough he won a national award for singing. I guess he is the only superstar who won national award for singing.
7. The silent movie Pushpaka Vimana got released in 4 languages. Pesum Padam (India: Tamil title) Pushpaka Vimana (India: Kannada title) Pushpaka Vimanam (India: Malayalam title) The Love Chariot (India: English title). And it was shot in Bangalore.
8. Famous DD serial Malgudi days was directed by Shankar Nag. He also directed “Swamy” later. He was the youngest director to direct Raj Kumar in Ondu Muthina Kathe.
9. Sati Sulochana released in 1934 was the first Kannada talkie movie was shot mostly at Chatrapathi Studio in Kolhapur.
10. Most famous conductor of kannada Cinema is Rajani and Most famous auto driver is Shankar Nag.
11. Rajanikanth debuted in Katha Sangama directed by Puttana Kanagal in 1975
12. Mungaru Male is the only movie to run more than one year in PVR cinemas
13. Balu Mahendra noted Tamil director started his career as director with the movie Kokila which got him National Award. He went on to direct Sadma later.
14. Kishan Shrikanth(Master Kishan) is the youngest person to direct a professional feature film. Movie: C/o Footpath
15. Puneet Rajkumar won the National Award for best child artist in “bettada huvu”
16. Arjun Sarja was one of the most celebrated child artist in Kannada film industry
17. The longest running Kannada movie was Bangarada Manushya with Rajkumar as hero. It did two years in States in Majestic.
18. The movie was directed by Siddalingaiah inspired many city lads to go back to villages and take farming.
19. Ilayaraja started his career as an assistant to noted Kannada music director GK Venkatesh
20. The first hero of Kannada cinema was Subbaiyanaidu.
21. I guess Kannada film industry has/had more engineers as heros than other Sudeep. Ramesh, Sunil etc
22. Bollywood singer Latha Mangeshkar’s first Kannada song Bellane Belagayithu. is for the film ‘Sangolli Rayanna’. Mohammad Rafi’s Ninelli Nadave Dhoora. And Kishore Kumar’s Aadu Aata Aadu.
23. ‘Samskara’ is the first ever Kannada film to get the President’s Gold Medal. The wave of new cinema started from then on. Girish Karnad made debut as an actor in this film.
24. Atul Kulkarni of Rang De Basanti and Hey Ram started his film career through Bhoomigite directed by Kesari. The film won a National Award in a special category

Update: Added some more with reader contribution. Lets make it List of 101 Things you did not know about Kannada Movies. Put those interesting stuff in comments. I will add to the main article.