Welcome to 536 King Street East! A Rare Income-Generating Opportunity in the Heart of Oshawa's Desirable O'Neill Community! This beautifully updated 4-bedroom detached home sits proudly on a premium corner lot, offering a unique blend of historic charm, modern upgrades, and impressive investment potential. Zoned R1-C, this property permits up to two additional accessory apartments, making it ideal for multi-generational families or savvy investors seeking to maximize rental income. Step inside to discover a bright, open-concept main floor featuring a spacious living room with a gas fireplace, French doors, and sliding doors that lead to a sun-filled 4-season sunroom perfect for year-round enjoyment. The modern kitchen (renovated in 2019) is a chef's dream with granite countertops, stainless steel appliances, a large center island, glass tile backsplash, and a sleek stainless steel hood fan and pantry. Upstairs, you'll find four generously sized bedrooms, all with hardwood flooring, and renovated bathrooms with contemporary finishes. One of the bedrooms features walk-out access to a private upper-level deck, providing a peaceful escape or dining area. The partially finished basement features a renovated 3-piece bathroom, cold cellar, and large recreational space, all ready for your vision. The basement has a rough-in for a kitchen. Enjoy peace of mind with recent updates: Furnace & A/C (2019), shingles (2022), hot water tank (owned, 2023), and washer/dryer on stands (2019). Outside, the fully fenced backyard features a large deck and a storage shed, ideal for entertaining, gardening, or creating your outdoor retreat. Close to top-rated schools, parks, transit, and shopping. A safe and family-friendly community with excellent walkability. Investment-ready with flexible zoning. Don't miss your chance to own a versatile and well-maintained home in one of Oshawa's most established neighbourhoods.