Americium(III) hydroxide is a radioactive inorganic compound with the chemical formula Am(OH)3.

As described by the Oak Ridge National Laboratory, americium is added to hydrochloric acid, then neutralized using ammonium hydroxide (NH4OH).

The americium oxalate is then filtered out, washed with water, and is partially dried by allowing exposure to air.

When decomposition begins to occur, the oxalate will turn into the desired black americium dioxide.

Further oxidation using ozone and sodium hydroxide can produce yellow hydroxy species of Am(VI).