After signing with WWE in 2010 under the ring name Dean Ambrose, Jon Moxley competed in their developmental territories Florida Championship Wrestling and NXT until 2012. He joined the main roster in November 2012 as a member of The Shield with Roman Reigns and Seth Rollins. Ambrose won his first championship in WWE while in the group, the United States Championship, with his 351-day reign being the longest under the WWE banner. Following The Shield's breakup, Ambrose went on to become a one-time WWE Champion, a three-time Intercontinental Champion, and a two-time Raw Tag Team Champion (with Rollins). He was also the 2016 Money in the Bank ladder match winner. Upon winning the Raw Tag Team Championship in August 2017, Ambrose became the 27th Triple Crown Champion and the 16th Grand Slam Champion.
Following his departure from WWE, Moxley made an unannounced appearance at AEW's premiere event, AEW Double or Nothing, reverting back to his Jon Moxley moniker. He also started working in NJPW shortly after his WWE exit and won the IWGP United States Championship in his NJPW debut, becoming the first and only wrestler to have held the WWE and IWGP United States championships.
In a recent interview with NJPW’s official website, the former WWE superstar revealed his goals in NJPW: “As United States Champion, I think I’ve gotta settle the score with Juice Robinson. Before I do anything else, that’s number one on the agenda. So let’s get an answer, sign the contract, get the plane tickets and get that out the way. After I put him in the ground, I plan on remaining US Champion.
After that I’m sure there’ll be a lot of people gunning for that title. I’ll have my head on a swivel, there’ll be challengers coming from all directions. Already there are people who beat me for the G1, so they could make a case to challenge me. People could pop out all of a sudden and then we have an issue.”