1,1'-Ferrocenedicarboxylic acid is the organoiron compound with the formula Fe(C5H4CO2H)2.

It is the simplest dicarboxylic acid derivative of ferrocene.

It is a yellow solid that is soluble in aqueous base.

The 1,1' part of its name refers to the location of the carboxylic acid groups on separate rings.

It can be prepared by hydrolysis of its diesters Fe(C5H4CO2R)2 (R = Me, Et), which in turn are obtained by treatment of ferrous chloride with the sodium salt of the carboxyester of cyclopentadienide (C5H4CO2R)−.