Tom Welling -- Superman's Wife Files for Divorce

Tom Welling is like Kryptonite to his wife -- she's filed to divorce the "Smallville" star ... TMZ has learned.

Jamie White Welling filed the docs on October 16, and in the papers she cites "irreconcilable differences" as the reason for their break-up.

Jamie is asking for spousal support.

According to the docs, Tom and Jamie separated in December 2012 after 10 years of marriage.

Tom and Jamie spent most of their time in Vancouver ... near where "Smallville" was filmed -- but moved to L.A. in 2011.