Whisk olive oil, ranch dressing, Worcestershire sauce, rosemary, sugar, salt, lemon juice, vinegar, and pepper together in a large bowl; let stand for 5 minutes. Add chicken to the bowl and toss to evenly coat. Cover the bowl with plastic wrap and marinate in the refrigerator for 30 minutes.

Preheat an outdoor grill for medium-high heat and lightly oil the grate.

Remove chicken from marinade and shake off excess. Thread marinated chicken onto skewers; discard remaining marinade.

Cook chicken skewers on the preheated grill until no longer pink in the center and the juices run clear, 4 to 6 minutes per side. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).