Britney Spears was anything but thrilled to have sheriff’s deputies knocking at her door close to midnight … all thanks to some fans who thought their favorite singer may be in danger.

Sources connected to Spears tell us Brit was left “annoyed” after the unexpected visit. We’re told she understands how deeply her fans care about her and her well-being, so she wasn’t totally surprised things escalated to law enforcement’s involvement … but nonetheless, it was an inconvenience.

TMZ broke the story, deputies from the Ventura County Sheriff’s Office paid Britney a visit at her Thousand Oaks home Tuesday night around 11PM to perform a welfare check.

Law enforcement sources told us they received several calls from fans who became concerned for Britney’s safety after she deleted her Instagram account.

We should note, Britney has deleted her IG several times before and our sources say she did it again, this time without a real reason … sometimes, she just feels like it.

The incident comes just days after Britney announced she was changing her name to River Red on IG.

TMZ broke the story, Britney and her husband, Sam Asghari, recently hit Joey in Woodland Hills for dinner — but the evening went awry — witnesses tell us Britney was acting “manic” to the point of Sam leaving.

Video, obtained by TMZ, showed the singer alone at the couple’s table and rambling incoherently.

Sam has since claimed he only left to get the couple’s car.