The event will feature Little Big Town, Elle King, Judah & the Lion, Cam, Perry & Etty Farrell and others.
The second annual country and Americana celebration rounded off in fine style, as large crowds enjoyed a day filled with sunshine and authentic roots music.
The first day of the multi-city festival's showpiece London event also featured an outstanding performance by Cam and many other highlights.
Frequent UK visitor Underwood will play the five arena shows in June and July.
uDiscover reviews the London edition of C2C 2017, the Country to Country Festival, with major current country stars, revered heritage acts and new names.
Reba McEntire has been announced as the third headliner at the 2017 Country to Country Festival, joining fellow giants Brad Paisley and the Zac Brown Band.
uDiscover presents audio excerpts from Paul Sexton's interview with Vince Gill, as he explains his decades-long love affair with Nashville.
For the first time in five years, there's a new solo album imminent from Grammy-winner Vince Gill. He will release Down To My Last Bad Habit on 12 February.