Prospectus by Investment Company (Form 497)

With respect to the Bond Index Fund, the table under the heading "Fees and Expenses" on page 2 of the Prospectus is hereby deleted and replaced with the following:

Class A
Shares

Class R
Shares

Class R6
Shares

Institutional
Service
Class Shares

Maximum Sales Charge (Load) imposed on purchases (as a percentage of offering price)

2.25%

None

None

None

Class A
Shares

Class R
Shares

Class R6
Shares

Institutional
Service
Class Shares

Management Fees

0.18%

0.18%

0.18%

0.18%

Distribution and/or Service (12b-1) Fees

0.25%

0.50%

None

None

Other Expenses

0.30%

0.38%

0.13%

0.38%

0.73%

1.06%

0.31%

0.56%

Fee Waiver/Expense Reimbursement⁽¹⁾

(0.11)%

(0.11)%

(0.11)%

(0.11)%

0.62%

0.95%

0.20%

0.45%

Nationwide Mutual Funds (the "Trust") and Nationwide Fund Advisors (the "Adviser") have entered into a written contract limiting annual fund operating expenses to 0.20% until at least April 1, 2027. Under the expense limitation agreement, the level to which operating expenses are limited applies to all share classes, excluding any taxes, interest, brokerage commissions, Rule 12b-1 fees, acquired fund fees and expenses, short-sale dividend expenses, administrative services fees, other expenses which are capitalized in accordance with generally accepted accounting principles and expenses incurred by the Fund in connection with any merger or reorganization, and may exclude other nonroutine expenses not incurred in the ordinary course of the Fund's business. The expense limitation agreement may be changed or eliminated only with the consent of the Board of Trustees of the Trust. The Adviser may request and receive reimbursement from the Fund for advisory fees waived or other expenses reimbursed by the Adviser pursuant to the expense limitation agreement at a date not to exceed three years from the date in which the corresponding waiver or reimbursement to the Fund was made. However, no reimbursement may be made unless: (i) the Fund's assets exceed $100 million and (ii) the total annual expense ratio of the class making such reimbursement is no higher than the amount of the expense limitation that was in place at the time the Adviser waived the fees or reimbursed the expenses and does not cause the expense ratio to exceed the current expense limitation. Reimbursement by the Fund of amounts previously waived or reimbursed by the Adviser is not permitted except as provided for in the expense limitation agreement.

With respect to the Bond Index Fund, the table under the heading "Example" beginning on page 2 of the Prospectus is hereby deleted and replaced with the following:

Class A Shares

Class R Shares

Class R6 Shares

Institutional Service Class Shares

With respect to the Mid Cap Market Index Fund, the table under the heading "Fees and Expenses" on page 11 of the Prospectus is hereby deleted and replaced with the following:

Maximum Sales Charge (Load) imposed on purchases (as a percentage of offering price)

5.75%

None

None

None

Management Fees

0.20%

0.20%

0.20%

0.20%

Distribution and/or Service (12b-1) Fees

0.25%

0.50%

None

None

Other Expenses

0.23%

0.33%

0.08%

0.31%

0.68%

1.03%

0.28%

0.51%

Fee Waiver/Expense Reimbursement⁽¹⁾

(0.03)%

(0.03)%

(0.03)%

(0.03)%

0.65%

1.00%

0.25%

0.48%

Nationwide Mutual Funds (the "Trust") and Nationwide Fund Advisors (the "Adviser") have entered into a written contract limiting annual fund operating expenses to 0.25% until at least April 1, 2027. Under the expense limitation agreement, the level to which operating expenses are limited applies to all share classes, excluding any taxes, interest, brokerage commissions, Rule 12b-1 fees, acquired fund fees and expenses, short-sale dividend expenses, administrative services fees, other expenses which are capitalized in accordance with generally accepted accounting principles and expenses incurred by the Fund in connection with any merger or reorganization, and may exclude other nonroutine expenses not incurred in the ordinary course of the Fund's business. The expense limitation agreement may be changed or eliminated only with the consent of the Board of Trustees of the Trust. The Adviser may request and receive reimbursement from the Fund for advisory fees waived or other expenses reimbursed by the Adviser pursuant to the expense limitation agreement at a date not to exceed three years from the date in which the corresponding waiver or reimbursement to the Fund was made. However, no reimbursement may be made unless: (i) the Fund's assets exceed $100 million and (ii) the total annual expense ratio of the class making such reimbursement is no higher than the amount of the expense limitation that was in place at the time the Adviser waived the fees or reimbursed the expenses and does not cause the expense ratio to exceed the current expense limitation. Reimbursement by the Fund of amounts previously waived or reimbursed by the Adviser is not permitted except as provided for in the expense limitation agreement.

With respect to the Mid Cap Market Index Fund, the table under the heading "Example" on page 11 of the Prospectus is hereby deleted and replaced with the following:

Class A Shares

Class R Shares

Class R6

Shares

Institutional Service Class

Shares