Exhibit 5.1

SUITE 1000 VOLUNTEER BUILDING

832 GEORGIA AVENUE

CHATTANOOGA, TENNESSEE 37402-2289

FAX (423) 785-8480

August 13, 2007

Unum Group

1 Fountain Square

Chattanooga, Tennessee 37402

RE:	Registration Statement on Form S-8 —
	Unum Group Stock Incentive Plan of 2007

Ladies and Gentlemen:

We have acted as counsel to Unum Group, a Delaware corporation (the “Company”), in connection with the filing of its Registration Statement on Form S-8 (the “Registration Statement”) with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”), and covering 35,000,000 shares (the “Shares”) of the common stock, $0.10 par value (the “Common Stock”), of the Company that may be issued pursuant to the Unum Group Stock Incentive Plan of 2007 (the “Plan”).

We have examined the Restated Certificate of Incorporation of the Company, the Amended and Restated Bylaws of the Company, the Plan, the Registration Statement and such other records, documents, instruments and certificates, and we have made such further legal and factual examinations and investigations, as we have deemed necessary, relevant or appropriate to enable us to render the opinion expressed below. In rendering our opinion, we have relied to the extent we deem such reliance appropriate as to certain matters on statements, representations and other information obtained from public officials, officers of the Company and other sources believed by us to be responsible.

Based on the foregoing, we are of the opinion that the Shares covered by the Registration Statement, when issued in accordance with the terms and conditions of the Plan, will be legally issued, fully paid and non-assessable shares of Common Stock of the Company.

The foregoing opinion is limited to the federal laws of the United States and to the General Corporation Law of the State of Delaware, and we express no opinion with respect to the laws of any other jurisdiction. We assume no obligation to supplement this opinion if any applicable laws change, or if we become aware of any facts that might change the opinion expressed, after the date hereof.

We hereby consent to the filing of this opinion letter as an exhibit to the Registration Statement in accordance with the requirements of Item 8 of Form S-8 and Item 601(b)(5) of Regulation S-K under the Act. In giving such consent, we do not admit that we are within the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.

Very Truly Yours,

MILLER & MARTIN PLLC

/s/ Miller & Martin PLLC