A voltage generation circuit may include: a main code table suitable for outputting a main code based on an operation signal; a main voltage generator suitable for generating a main voltage corresponding to the main code; a trimming module suitable for comparing the main voltage with a target voltage to output a trimming signal; a trimming code table suitable for outputting a trimming code corresponding to the trimming signal; a code determination module suitable for outputting the main code and the trimming code when the trimming code is determined to be valid, and outputting the main code and a output code when the trimming code is determined to be invalid; and an operation voltage generator suitable for outputting an operation voltage based on the main code and a code selected from the trimming code and the substitute code.