Melt the white chocolate chips in a bowl set over a pot of simmering water and stir until smooth. You can also do this in the microwave, heating the chocolate for 30 seconds at a time, then stirring, until fully melted.
Add the popped popcorn to a large bowl and pour the melted white chocolate over it. Add a pinch or two of salt along with the funfetti sprinkles and stir to combine.
Spread the coated popcorn on a sheet pan lined with parchment paper and allow it to cool.
Store any leftovers in an air-tight container on the counter.