Place a large skillet over medium-high heat.
Add the ground beef and diced onion to the skillet.
Cook while breaking the beef into small crumbles with a wooden spoon or spatula. Continue cooking until the beef is completely browned and the onion has softened.
Carefully drain the excess fat from the skillet.
Transfer the cooked ground beef and onion mixture to the bowl of your slow cooker.
Cut the Velveeta cheese and cream cheese into cubes. Smaller cubes will melt more evenly and quickly.
Add the cubed Velveeta and cream cheese to the slow cooker.
Add the diced jalapeño, salsa, diced green chilies, and hot sauce.
Gently stir the ingredients together. They do not need to be completely combined at this stage because the cheeses will still be firm.
Place the lid on the slow cooker.
Cook the Slow Cooker Beef Queso Dip on LOW for approximately 3 hours.
About halfway through cooking, remove the lid and stir thoroughly, bringing the partially melted cheese from the sides and bottom into the center.
Replace the lid and continue cooking until the cheese is completely melted and the dip is hot and creamy.
Stir the queso thoroughly before serving. Make sure the ground beef and vegetables are evenly distributed throughout the cheese.
Taste carefully and adjust the heat with another dash of hot sauce if desired.
Switch the slow cooker to the WARM setting for serving if your appliance has one.
Serve warm with tortilla chips or your favorite dippers.