The middle Jonas Brother dated Swift in 2008 and was reported to have ended their romance in a phone call.
Speaking to E!'s Daily 10, he said: "We've actually recently reconnected, which is good. I hope she gets a Grammy. She deserves it."
Swift, 19, is nominated in eight categories at the annual music ceremony, including 'Album Of The Year', 'Song Of The Year' and 'Record Of The Year'.
Jonas also opened up about older brother Kevin's recent marriage to girlfriend Danielle Deleasa, saying: "They love each other so much. I'm really happy for him... I can't believe it. I hope I have that one day."
> Jonas laughs off Duff romance rumours