Many of them are looking forward to his much-anticipated birthday bash at Taj Lands End here.
After giving two back-to-back hits "Agneepath" and "Ekk Main Aur Ekk Tu" this year, Karan - son of the legendary filmmaker Yash Johar - is currently gearing up for a hatrick with "Student of the Year".
"Happy Happy Birthday. Love your spirit! Looking forward to the most amazing and anticipated party in a long time. I love birthdays," Bipasha Basu posted on Twitter.
"Been busy with kids, organising home, went saw Shilpa and Raj's cute little son. Touchwood, tonight Karans 40th bash!! When works not hectic," said Raveena Tandon.
"Wishing my dearest friend a very happy birthday. Thank you for always being there for me - LOVE YOU LOADS," tweeted Riteish Deshmukh.
"Wishing a very happy 40th birthday to a creative Genius! May you keep knocking out super hits after super hits!," Raj Kundra posted.
"Happy Birthday to a truly super guy, with the most evil and brilliant sense of humour. Wish you great joy, great health, great films!," posted composer Vishal Dadlani.
"Happy happy happppy bday kjohar25!! Have a soooper doooper awesome year! (sic)," Shreya Ghoshal.
"Happy Birthday, Karan! Yash would be so proud of all you've achieved! Wishing you decades of fulfilment," posted Kabir Bedi.
