What is the weakest type of chemical bond

An ionic bond is weakest bond. A Chemical bond is technically a bond between two atoms that results in the formation of a molecule , unit formula or polyatomic ion.

The weakest of the intramolecular bonds or chemical bonds is the ionic bond. next the polar covalent bond and the strongest the non polar covalent bond.

There are even weaker intermolecular  bonds  or more correctly forces. These intermolecular forces bind molecules to molecules.

The strongest of these intermolecular forces is the Hydrogen Bond found in water. The  Hydrogen Bond is not actually a chemical but an intermolecular force or attraction. Other intermolecular forces are the Van der Walls interactions and the dipole dipole attractions.

The ionic bond is generally the weakest of the true chemical bonds that bind atoms to atoms.