Melissa Benoist just filed court docs seeking to end her 4 year marriage to Blake Jenner ... who played Ryder Lynn on "Glee" after winning the role on Oxygen's "The Glee Project."

Both 28-year-old Melissa and 24-year-old Blake later got roles on CW's "Supergirl" -- where Melissa plays the main superhero ... and Blake appeared on 2 episodes.

In the court docs, Melissa cites "irreconcilable differences" for the split -- and wants to block the court's ability to dish out spousal support to either of them.

They have no kids ... so no issues there.

One last thing, she wants to change her legal name back to Melissa Benoist ... and drop the Jenner thing for good.

Seems to be the only person in Hollywood who doesn't want to be a Jenner these days.