To deafening loud cheers at the crucible of Russian and Soviet sports, former Spain goalkeeper Iker Casillas held up the golden trophy for fans to photograph.
Outside the refurbished stadium, colourful crowds of fans danced and chanted, with a heavy police presence keeping order.
The mood was festive and peaceful, with Russian fans cheering a group of Saudi fans in green who were congregating outside one of the entrances.
The opening ceremony included a mini-concert by British pop star Robbie Williams, who performed "Let Me Entertain You".
Russian President Vladimir Putin and FIFA boss Gianni Infantino officially open the tournament minutes before the 1500 GMT kickoff.
A bellowing chant of "Russia!" echoed through the packed stadium as the opening ceremony got under way to music from Russian composer Pyotr Tchaikovsky.