Gather all ingredients.

Bring a large pot of lightly salted water to a boil. Cook spaghetti in boiling water, stirring occasionally, until tender yet firm to the bite, about 12 minutes; drain, then rinse with cold water to cool.

Meanwhile, whisk soy sauce, teriyaki sauce, honey, and ginger together in a small bowl; set aside.

While the spaghetti cooks, heat oil in a large skillet or wok over high heat. Cook and stir celery, carrots, onion, and green onions until slightly tender, 5 to 7 minutes.

Add spaghetti and soy sauce mixture. Cook, stirring frequently, until heated through and evenly coated, about 2 to 3 minutes. Serve garnished with additional sliced green onions, if desired.