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                                                                      Exhibit 24


                                 OM Group, Inc.

                                    Form 10-K
                         Power of Attorney for Directors

The undersigned, a director of OM Group, Inc., a Delaware corporation (the
"Company"), which anticipates the filing with the Securities and Exchange
Commission (the "Commission") under the provisions of the Securities Exchange
Act of 1934 (the "Act") a Form 10-K (together with any and all subsequent
amendments, the "Form 10-K"), does hereby constitute and appoint James P.
Mooney, Thomas R. Miklich or Michael J. Scott and any one of them with full
power of substitution and resubstitution, as attorney or attorneys to execute
and file on behalf of the undersigned, in his capacity as director of the
Company, the Form 10-K and any and all other documents to be filed with the
Commission pertaining to the Form 10-K, with full power and authority to do and
perform any and all acts and things whatsoever required or necessary to be done
in the premises, as fully as to all intents and purposes a she could do if
personally present, hereby ratifying and approving the acts of said attorneys
and any of them and any such substitution.

Executed this 24th day of March 2003.

                                                            /s/ Markku Toivanen
<PAGE>
                                 OM Group, Inc.

                                    Form 10-K
                         Power of Attorney for Directors

The undersigned, a director of OM Group, Inc., a Delaware corporation (the
"Company"), which anticipates the filing with the Securities and Exchange
Commission (the "Commission") under the provisions of the Securities Exchange
Act of 1934 (the "Act") a Form 10-K (together with any and all subsequent
amendments, the "Form 10-K"), does hereby constitute and appoint James P.
Mooney, Thomas R. Miklich or Michael J. Scott and any one of them with full
power of substitution and resubstitution, as attorney or attorneys to execute
and file on behalf of the undersigned, in his capacity as director of the
Company, the Form 10-K and any and all other documents to be filed with the
Commission pertaining to the Form 10-K, with full power and authority to do and
perform any and all acts and things whatsoever required or necessary to be done
in the premises, as fully as to all intents and purposes a she could do if
personally present, hereby ratifying and approving the acts of said attorneys
and any of them and any such substitution.

Executed this 24th day of March 2003.

                                                              /s/ Lee R. Brodeur
<PAGE>
                                 OM Group, Inc.

                                    Form 10-K
                         Power of Attorney for Directors

The undersigned, a director of OM Group, Inc., a Delaware corporation (the
"Company"), which anticipates the filing with the Securities and Exchange
Commission (the "Commission") under the provisions of the Securities Exchange
Act of 1934 (the "Act") a Form 10-K (together with any and all subsequent
amendments, the "Form 10-K"), does hereby constitute and appoint James P.
Mooney, Thomas R. Miklich or Michael J. Scott and any one of them with full
power of substitution and resubstitution, as attorney or attorneys to execute
and file on behalf of the undersigned, in his capacity as director of the
Company, the Form 10-K and any and all other documents to be filed with the
Commission pertaining to the Form 10-K, with full power and authority to do and
perform any and all acts and things whatsoever required or necessary to be done
in the premises, as fully as to all intents and purposes a she could do if
personally present, hereby ratifying and approving the acts of said attorneys
and any of them and any such substitution.

Executed this 24th day of March 2003.

                                                           /s/ William J. Reidy
<PAGE>
                                 OM Group, Inc.

                                    Form 10-K
                         Power of Attorney for Directors

The undersigned, a director of OM Group, Inc., a Delaware corporation (the
"Company"), which anticipates the filing with the Securities and Exchange
Commission (the "Commission") under the provisions of the Securities Exchange
Act of 1934 (the "Act") a Form 10-K (together with any and all subsequent
amendments, the "Form 10-K"), does hereby constitute and appoint James P.
Mooney, Thomas R. Miklich or Michael J. Scott and any one of them with full
power of substitution and resubstitution, as attorney or attorneys to execute
and file on behalf of the undersigned, in his capacity as director of the
Company, the Form 10-K and any and all other documents to be filed with the
Commission pertaining to the Form 10-K, with full power and authority to do and
perform any and all acts and things whatsoever required or necessary to be done
in the premises, as fully as to all intents and purposes a she could do if
personally present, hereby ratifying and approving the acts of said attorneys
and any of them and any such substitution.

Executed this 24th day of March 2003.

                                                           /s/ John E. Mooney
<PAGE>
                                 OM Group, Inc.

                                    Form 10-K
                         Power of Attorney for Directors

The undersigned, a director of OM Group, Inc., a Delaware corporation (the
"Company"), which anticipates the filing with the Securities and Exchange
Commission (the "Commission") under the provisions of the Securities Exchange
Act of 1934 (the "Act") a Form 10-K (together with any and all subsequent
amendments, the "Form 10-K"), does hereby constitute and appoint James P.
Mooney, Thomas R. Miklich or Michael J. Scott and any one of them with full
power of substitution and resubstitution, as attorney or attorneys to execute
and file on behalf of the undersigned, in his capacity as director of the
Company, the Form 10-K and any and all other documents to be filed with the
Commission pertaining to the Form 10-K, with full power and authority to do and
perform any and all acts and things whatsoever required or necessary to be done
in the premises, as fully as to all intents and purposes a she could do if
personally present, hereby ratifying and approving the acts of said attorneys
and any of them and any such substitution.

Executed this 24th day of March 2003.

                                                              /s/ Frank Butler
<PAGE>
                                 OM Group, Inc.

                                    Form 10-K
                         Power of Attorney for Directors

The undersigned, a director of OM Group, Inc., a Delaware corporation (the
"Company"), which anticipates the filing with the Securities and Exchange
Commission (the "Commission") under the provisions of the Securities Exchange
Act of 1934 (the "Act") a Form 10-K (together with any and all subsequent
amendments, the "Form 10-K"), does hereby constitute and appoint James P.
Mooney, Thomas R. Miklich or Michael J. Scott and any one of them with full
power of substitution and resubstitution, as attorney or attorneys to execute
and file on behalf of the undersigned, in his capacity as director of the
Company, the Form 10-K and any and all other documents to be filed with the
Commission pertaining to the Form 10-K, with full power and authority to do and
perform any and all acts and things whatsoever required or necessary to be done
in the premises, as fully as to all intents and purposes a she could do if
personally present, hereby ratifying and approving the acts of said attorneys
and any of them and any such substitution.

Executed this 24th day of March 2003.

                                                        /s/ Katharine L. Plourde