Riverdale gets mentioned in The Boys (2019), of all tv shows, in episode 2 of Season 4. Apparently, Homelander is planning a birthday party where the Riverdale cast is invited.
It's also referenced in Season 1 of Never Have I Ever when Devi and her cousin Kamala watch some episodes of Season 1. For example, the moment Betty confronts her mother to defend her relatioship with Jughead after the Homecoming was inspirational for Kamala about her own love life issues.
Season 5 is referred in Season 4 of Titans (2018), in a dream sequence.
In Season 4 of Doom Patrol (2019), at one point, Robotman quotes, word for word, Jughead's memetic "In case you haven't noticed, I'm weird" monologue.
