But just what did he say?
It was the final show of The Voice 2019 Saturday (April 6) as the four remaining singers performed for victory.
Team Tom's Deana Walmsley and Bethzienna Williams together with Team Olly's Jimmy Balito and Molly Hocking battled it out for viewer votes.
Molly and Deana made the top two following the first round of live performances, which saw Jimmy and Bethzienna eliminated.
But when that result was announced, there was apparently some 'bad language' from Sir Tom Jones.
"Something may have slipped out of Tom Jones' mouth, I'm sorry," host Emma Willis said.
A puzzled Tom reacted: "What did I say?!"
Those watching at home were equally confused, unsure of what was apparently said to warrant the apology.
A few alleged Sir Tom could be heard saying 'Thank f**k' as his act Deana made it through, but most people didn't hear anything.
And even if Sir Tom did swear, many didn't think there was any need for an apology.
"Why make a deal out of Tom Jones letting slip a little swear word?! Nobody even noticed and it’s gone 10pm ffs!" one Twitter user wrote. "Bringing it up makes more of a deal!! Anyway he’s Tom Jones he can do what ever the f**k he wants #thevoiceuk."
Another added: "If Tom Jones wants to swear, he can f**king swear. Okay? #TheVoice"
Meanwhile, others begged the coaches to spill on what was actually said.
One asked Olly Murs: "@ollyofficial what did #TomJones say..... You've got to spill the beans"
Sir Tom's act Deana went on to finish runner up in the final result as Team Olly's Molly was crowned the winner of The Voice 2019.
The Voice UK airs on ITV.
You can catch up with full episodes from series 8 via the ITV Hub.