Exhibit 5(a)



                                                July 11, 2003


Ohio Power Company
1 Riverside Plaza
Columbus, Ohio  43215

Ladies and Gentlemen:

            We have acted as counsel to Ohio Power Company, an Ohio corporation
(the "Company"), in connection with the Registration Statement on Form S-3 (File
No. 333-106242) filed by the Company with the Securities and Exchange Commission
(the "Commission") under the Securities Act of 1933, as amended (the "Act"),
relating to $225,000,000 aggregate principal amount of 4.85% Senior Notes,
Series H, due 2014 and $225,000,000 aggregate principal amount of 6.375% Senior
Notes, Series I, due 2033 (collectively, the "Senior Notes") between the Company
and Deutsche Bank Trust Company Americas (formerly Bankers Trust Company), as
Trustee (the "Trustee").

            We have examined the Registration Statement and the Indenture, which
has been filed with the Commission as an exhibit to the Registration Statement.
We also have examined the originals, or duplicates or certified or conformed
copies, of such records, agreements, instruments and other documents and have
made such other and further investigations as we have deemed relevant and
necessary in connection with the opinions expressed herein. As to questions of
fact material to this opinion, we have relied upon certificates of public
officials and of officers and representatives of the Company.

            In rendering the opinions set forth below, we have assumed the
genuineness of all signatures, the legal capacity of natural persons, the
authenticity of all documents submitted to us as originals, the conformity to
original documents of all documents submitted to us as duplicates or certified
or conformed copies and the authenticity of the originals of such latter
documents. We also have assumed that: (1) the Indenture is the valid and legally
binding obligation of the Trustee; and (2) the Company is validly existing under
the laws of Ohio.

            We have assumed further that (1) the Company has duly authorized,
executed and delivered the Indenture and (2) execution, delivery and performance
by the Company of Indenture and the Unsecured Notes do not and will not violate
the laws of Ohio or any other applicable laws (excepting the laws of the State
of New York and the Federal laws of the United States).

            Based upon the foregoing, and subject to the qualifications and
limitations stated herein, we are of the opinion that the Senior Notes
constitute valid and legally binding obligations of the Company enforceable
against the Company in accordance with their terms, subject to the effects of
(i) bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium
and other similar laws relating to or affecting creditors' rights generally,
(ii) general equitable principles (whether considered in a proceeding in equity
or at law) and (iii) an implied covenant of good faith and fair dealing.

            We are members of the Bar of the State of New York, and we do not
express any opinion herein concerning any law other than the law of the State of
New York and the Federal law of the United States.

            We hereby consent to the filing of this opinion letter as Exhibit
5(b) to the Registration Statement and to the use of our name under the caption
"Legal Opinions" in the Prospectus included in the Registration Statement.

                                    Very truly yours,

                                    /s/ Simpson Thacher & Bartlett LLP

                                    SIMPSON THACHER & BARTLETT LLP