The winner of the Big Brother Blockbuster Week 13 was Lauren. She won the Blockbuster challenge, outperforming competitors Keanu and Kelley in that round of the game.

If the question was about Bigg Boss 13 (the Indian version), the winner of that season was Sidharth Shukla. But specifically for the "Blockbuster" challenge in Week 13 of Big Brother (the US version), the winner was Lauren.