The longest winning streak in the 2026 MLB season stands at 15 games by the Boston Red Sox in July, tying a franchise record but falling well short of modern-era marks like the 2017 Indians' 22-game run. No team has approached or exceeded that total in the months since, with the Dodgers' current six-game streak representing the longest active mark as the regular season nears its end. Late-September scheduling, bullpen management, and playoff positioning make extended runs unlikely, reinforcing trader consensus around a 13-15 game ceiling. A late surge by a surging contender could theoretically push higher, though historical patterns and the compressed calendar limit realistic upside beyond 15 games.