Led by LiveNation, it was surprise announced on the same day as the ticket sale by Aguilera herself on March 4, 2019, and serves as the European counterpart to The Liberation Tour the year before.

Katie Hawthorne of The Guardian opined that "this dazzling spectacle feels almost like a one-woman variety show, were it not for the eight dancers, three singers, full band and mountain of glitter".

[16] Tim Heap, writing for the gay-themed magazine Attitude, commended on the show's setlist: "For every high-energy banger, from a reworked 'Genie in a Bottle' to a 'Candyman'/'I Want Candy' mash-up, there’s a ballad that really lets the vocals soar".

[17] Katie Fitzpatrick from Manchester Evening News wrote that, "From the punchy pop of 'Ain’t No Other Man' to the bugle bop on 'Candyman', this is a flawless and full-throttle journey through Aguilera's career—and the costumes are fabulous".

[18] Helsingin Sanomat's Anton Vanha-Majamaa provided a positive review, and praised the tour for its feminist statements, intense theatricality, and rich choreography.

[20] Writing for Express & Star, Kirsten Rawlins stated that The X Tour was "a beautiful show from start to end, filled with messages of self-love, peace, and female empowerment—mixed in with smoulderingly sexy costumes and dance moves.