As of my knowledge cutoff date of September 2021, the highest-grossing movie of all time was "Avengers: Endgame" (2019), directed by Anthony and Joe Russo and produced by Marvel Studios. The movie grossed over $2.798 billion worldwide, surpassing the previous record-holder, "Avatar" (2009), directed by James Cameron, which grossed over $2.789 billion worldwide. It's worth noting that these records can change over time as new movies are released and box office totals are updated.