None so far but there's an identity thief a.k.a Craig Wright that filed for a copyright for the original Bitcoin whitepaper and for the source codes. I won't be surprised if he does it for the Bitcoin word too.
bitcoin.org is owned by bitcoin developers.
bitcoin.com is owned by person/people who provide bitcoin services.
But who owns the "Bitcoin" brand?
Bitcoin is not a company,so the name Bitcoin can't be considered a brand.Bitcoin is a currency.Can the other currencies (fiat and crypto) be considered as brands?Nobody is talking about whether or not the US dollar is a brand or who owns the term euro,because it would sound absurd.
The altcoin fork scammers took advantage of this situation and made several "Bitcoin"(BCH,BSV,Bitcoingold,etc..) projects that aren't actually Bitcoin.We can't do anything about that.

Bitcoin doesn't need to be a company to be trademarked. Anyone can file for a trademark even if it's just a word. Ask how Pat Riley did it for the "Three-Peat".