Preheat oven to 350°F. Line 3 large baking sheets with parchment paper. Set aside.
In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
To the bowl of a stand mixer with a paddle attachment, add the butter, brown sugar, granulated sugar, orange zest, and orange juice. Mix on medium speed until light and fluffy (3-5 minutes), stopping to scrape the sides of the bowl as needed.
With the mixer on low, add eggs, one at a time, mixing well after each addition.
To the butter and sugar mixture, add the dry ingredients and mix on low until just combined.
With the mixer still on low, add the white chocolate chips and walnuts until evenly distributed throughout the dough.
Using a 2-tablespoon scoop, drop the dough onto the lined baking sheets, leaving about 2 inches of space between each cookie.
Bake for 10-11 minutes, or until the edges turn golden brown. Let the cookies cool on the baking sheets for a few minutes before transferring to a wire rack to finish cooling.