Joseph Baena Not at Patrick Schwarzenegger's Wedding, Despite Reports

Joseph Baena did NOT make the cut for the final guest list of Patrick Schwarzenegger's wedding ... despite recent reports claiming otherwise, TMZ has learned.

Sources with direct knowledge tell TMZ ... Joseph didn't attend Patrick's wedding to Abby Champion in northern Idaho over the weekend, as he wasn't invited in the first place. Take that in!!!

We're told it isn't surprising that Joseph wasn't included in the wedding festivities, given he has no relationship with that side of the Schwarzenegger fam.

Remember, Joseph is the result of Arnold Schwarzenegger's affair with Mildred Peña, his and then-wife Maria Shriver's housekeeper. Joseph didn't learn that Arnold was his father until he was 13 ... when it became a nationwide scandal in 2010.

While Arnold has made a point to show up for Joseph over the years, supporting his look-alike son at his graduation and other events, the two sides of the family have yet to fully blend together.

For instance, Joseph was notably MIA from a family photo at the June premiere for Arnold's Netflix film, "Fubar." The ex-Governator posed for a pic with his children Katherine, 35, Christina, 34, Patrick, 31, and Christopher, 27 ... even son-in-law Chris Pratt was included in the photo.

However, later on in the premiere, Arnold posed for a snap with just Joseph on the red carpet.