Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the spaghetti, and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through, but is still firm to the bite, about 12 minutes. Drain well in a colander set in the sink.
Meanwhile, heat the olive oil in a large frypan over medium heat. Stir in the bacon and cook until the bacon has begun to shrink, about 3 minutes. Add the garlic and continue cooking and stirring until the garlic has softened and the bacon is crisp, about 5 minutes. Toss the drained pasta with the bacon, oil and parsley to serve.