Heat olive oil in a large skillet over medium heat.
Add the chopped onion and cook for 3-4 minutes until softened.
Add the minced garlic and cook for 30 seconds until fragrant.
Add the ground beef to the skillet and cook, breaking it apart with a spoon, until browned and cooked through, about 6-8 minutes.
Drain excess fat from the skillet if necessary.
Stir in chili powder, ground cumin, paprika, dried oregano, crushed red pepper flakes, salt, and black pepper.
Add the tomato sauce and stir to combine. Reduce heat to low and simmer for 5 minutes to allow flavors to meld.
While the beef simmers, warm the corn tortillas in a dry skillet over medium heat for about 30 seconds on each side or until pliable.
To assemble the tacos, spoon the seasoned ground beef onto each tortilla.
Top each taco with shredded lettuce, diced tomatoes, shredded cheddar cheese, and chopped fresh cilantro.
Serve immediately with lime wedges on the side for squeezing over the tacos.