The 29-year-old singer noticed a white feather float past her as she was performing at the BB&T Center in Sunrise, Florida, on Wednesday night and believes it is a sign that spiritual beings are protecting her.
In a series of Twitter posts, she revealed: ''My favorite part of the night was when I was singing By the Grace of God & a little white feather (presumably from a costume) floated by ... & it reminded me about the angels & how, maybe, they are still looking after me, helping me continue to put one foot in front of the other.''
The appearance of the symbol was even more significant to Katy as it happened as she was performing 'By The Grace of God' - the track she wrote in the wake of her divorce from Russell Brand.
As well as believing in angels, Katy also believes in aliens. Raised by strict Christian pastor parents, she has become increasingly interested in extra-terrestrials and is convinced humans are not alone in the universe.
She previously said: ''I'm fascinated by that kind of stuff because of how I grew up, where everything was so black and white. Now I'm seeing a lot more colour in the world and asking more questions. So I'm very into things that are above and beyond me and were before me and will be after me ... I do hope that when the aliens come, they'll recognise me. I'll be like, 'Please don't kill me, I wrote a song called 'E.T.' ''