Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, combine the milk, vegetable oil, eggs, lemon zest, and lemon juice.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Divide the batter evenly among the muffin cups, filling each about ⅔ full.
Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Allow the muffins to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.