Welcome to 11259 Oak Brook Ct, a spacious pool home tucked away on a quiet cul-de-sac in the desirable Alta Loma area of Rancho Cucamonga, north of the 210. Situated on an approximately 11,000 sq. ft. lot with NO HOA, this two-story residence offers approximately 2,798 sq. ft. of living space with 4 bedrooms, 3 bathrooms, and an attached 3-car garage. Step inside to an impressive light-filled interior featuring soaring ceilings, oversized arched windows, elegant chandeliers, plantation shutters, and a graceful curved staircase. The formal living and dining areas provide generous space for entertaining, while the open kitchen features abundant cabinetry, granite countertops, a center island, gas cooktop, and casual dining area. The kitchen opens to the family room with a cozy fireplace, creating a comfortable and functional gathering space. A desirable main-level bedroom and bathroom provide added flexibility for guests, a home office, or multigenerational living. Upstairs, the expansive primary suite offers plenty of room to unwind and features direct access to a private balcony overlooking the backyard. The primary bath includes a soaking tub, separate shower, and abundant natural light. Two additional upstairs bedrooms complete the well-designed floor plan. The backyard is a true Southern California retreat, surrounded by mature palm trees and lush landscaping and featuring a private swimming pool and spa, spacious patio areas, covered outdoor entertaining space, and a large upper balcony overlooking the grounds. With an approximately quarter-acre lot, there is plenty of outdoor space to relax, entertain, and enjoy year-round. Recent improvements include a new water heater, gas cooktop, range hood, attic access door, brand-new SPC waterproof flooring in the family room, and updates to the pool equipment. Additional highlights include an indoor laundry room, high ceilings, abundant natural light, and a three-car garage. Conveniently located near shopping, dining, parks, and commuter routes, with nearby schools including Banyan Elementary, Vineyard Junior High, and Los Osos High School. This spacious Alta Loma pool home offers an exceptional combination of location, lot size, indoor-outdoor living, and everyday functionality.