Claudio Castagnoli (born December 27, 1980), also known by the ring name Antonio Cesaro, is a Swiss professional wrestler, signed with WWE, where he is the reigning United States Champion. He was previously known for his work (under his real name) in Ring of Honor (ROH), various independent promotions (most notably Pro Wrestling Guerrilla (PWG)), and the Japan-based Pro Wrestling NOAH.
Castagnoli is an accomplished tag team wrestler, being a two-time ROH World Tag Team Champion with his partner Chris Hero as the Kings of Wrestling (where their 364 day reign as champions was the longest in company history), as well various independent tag team titles both with Hero and with Ares as Swiss Money Holding. Castagnoli and Hero were voted as the 2010 Tag Team of the Year by Wrestling Observer Newsletter readers.
He has also had success as a singles wrestler, having won the WWE United States Championship along with numerous independent singles titles (most notably the PWG World Championship).
Particularly in America, Castagnoli emphasizes his European origin as part of his wrestling gimmick to proclaim a superior intellect and fashion sensibility, not only by speaking 4 languages (English, German, Italian, French), but also by his wrestling moves with European origins (eg. German Suplex, European uppercut, etc.)