Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or lightly grease with cooking spray.
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt until well combined.
In a separate bowl, mix the buttermilk, vegetable oil, egg, vanilla extract, lemon zest, and lemon juice until smooth.
Pour the wet ingredients into the dry ingredients and stir until just combined. Be careful not to overmix; a few lumps are okay.
Gently fold in the blueberries using a rubber spatula, being careful not to crush them.
Divide the batter evenly among the muffin cups, filling each about 3/4 full.
Bake for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Allow the muffins to cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.