"It's just us now," the "NCIS" actor wrote after popping the question to Amanda Pacheco.
"Thank all of you fans out there for your love and support," the actor said later.
The former "NCIS: New Orleans" showrunner is the fourth high-profile figure to be ousted from the network in the last year.
The actress appeared in three "NCIS" episodes last season.
The "NCIS" actress said earlier that a publicity "machine" was keeping her silent about the assaults.
CBS confirmed that Perrette "came to us with a workplace concern."
It's the best (and the worst) time of year.
Join actor, musician LL Cool J, who stars on "NCIS: Los Angeles" and hosts the hit "Lip Sync Battle" on Spike TV, as he comes to BUILD to talk about both shows.
His cousin, George Clooney, paid tribute to the actor on Thursday.