Usually. Most organic solvents (hydrocarbons) are non-polar and so are immiscible with water, and so form layers (like oil and water). Compounds like diethyl ether ("ether") and ethyl acetate (EtOAc) are less dense than water, and so appear in the top layer when mixed with water.

The most common exception to this rule are chloroform (CHCl3) and dichloromethane (also known as DCM or methylene chloride, CH2Cl2). These compounds are more dense than water, and so appear in the bottom later when mixed with water.

So overall: the organic layer is usually on top of the aqueous layer (as with ether or EtOAc). But with some solvents the aqueous layer is on top and the organic layer is on bottom (CHCl3 or CH2Cl2).

Not that some organic compounds like dimethylformamide (DMF) and dimethylsulfoxide (DMSO) are so polar that they are miscible with water (which is also very polar), and don't form layers.