Mariah Carey is the Queen of Christmas for a reason — and not just because “All I Want for Christmas Is You" tops the charts seasonally.

Carey has turned the song into an event, regularly hosting Christmas concerts to celebrate her undisputed smash and long career as a holiday icon. This year, she embarked on the “Christmas Time” tour, a variety show that kicked off on Nov. 6 in Highland, California, hitting many major North American cities, before concluding on Tuesday night at Barclays Center in Brooklyn.

It came to an end in front of a crowd donning shimmery Santa hats and red sequin party dresses. Carey descended onto the stage in a snowflake-shaped throne, leading the audience into a few church staples: “Silent Night” and “O Holy Night” among them.

Her children, twins Roc and Roe, joined in on the fun. At one point, Carey detoured into a medley of her biggest hits: “Emotions,” “Hero," “Fantasy,” and “We Belong Together” among them.

The latter moment came with an unexpected surprise: the elusive Rihanna was in the audience, and Carey signed her chest during an arena-wide sing-a-long of “Always Be My Baby.” Ri disappeared as quickly as she emerged, but Carey kept the momentum up, concluding the only way she could — with a spirited rendition of “All I Want for Christmas Is You.”

Earlier this year, Carey's first Christmas album, 1994's “Merry Christmas,” turned 30. She told The Associated Press she originally felt apprehensive to record a holiday album and then gave in to the festive spirit.

“I was very young and was just starting out and I felt like people do Christmas albums later in their lives. But now people have started to do them whenever, like right at the top of their career,” she said. “And I decorated the studio and just had the best time.”

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Krysta Fauria contributed to this report.