In a mixing bowl, whisk together the almond milk and protein powder until the powder is fully dissolved and no lumps remain.
Add the chia seeds, lemon juice, lemon zest, maple syrup, and vanilla extract to the milk mixture.
Whisk vigorously for 2 minutes to ensure the chia seeds are evenly distributed and do not clump at the bottom.
Cover the bowl or transfer the mixture into individual jars and refrigerate for a minimum of 4 hours, or overnight, until the pudding has thickened to a gelatinous consistency.
Stir the pudding once more before serving to redistribute any settled ingredients; add a splash of milk if a thinner consistency is preferred.