Filing by Investment Company (SEC Filing - 497)

Supplement Dated September 14, 2021

To The Statement of Additional Information

Dated April 26, 2021

JNL^® Series Trust

Please note that the changes may impact your variable annuity and variable life product(s).

All changes are effective September 13, 2021.

On page 141, in the section, 'Trustees and Officers of the Trust,' under, 'Selection of Trustee Nominees,' please delete the fourth paragraph in the entirety and replace with the following:

Shareholders should note that a person who owns securities issued by Jackson Financial, Inc. ('Jackson') would be deemed an 'interested person' under the 1940 Act. In addition, certain other relationships with Jackson or its subsidiaries, with registered broker-dealers, or with the Funds' outside legal counsel may cause a person to be deemed an 'interested person.' JNAM is an indirect, wholly owned subsidiary of Jackson, a leading provider of retirement products for industry professionals and their clients. Jackson and its affiliates offer variable, fixed and fixed index annuities designed for tax-efficient growth and distribution of retirement income for retail customers, as well as products for institutional investors. Prudential plc and Athene Life Re Ltd each hold a minority economic interest in Jackson. Prudential plc has no relation to Newark, New Jersey-based Prudential Financial Inc.

On page 165, in the section entitled, 'Investment Adviser, Sub-Advisers and Other Service Providers,' under 'Investment Adviser,' please delete the first paragraph in the entirety and replace with the following:

JNAM, 1 Corporate Way, Lansing, Michigan 48951, is the investment adviser to the Trust. As investment adviser, JNAM provides the Trust with professional investment supervision and management. JNAM is an indirect, wholly owned subsidiary of Jackson Financial Inc. ('Jackson'), a leading provider of retirement products for industry professionals and their clients. Jackson and its affiliates offer variable, fixed and fixed index annuities designed for tax-efficient growth and distribution of retirement income for retail customers, as well as products for institutional investors. Prudential plc and Athene Life Re Ltd each hold a minority economic interest in Jackson. Prudential plc has no relation to Newark, New Jersey-based Prudential Financial Inc.

On page 222-223, in the section entitled, 'Investment Adviser, Sub-Advisers and Other Service Providers,' under 'Investment Sub-Advisers and Portfolio Managers,' for Jackson National Asset Management, LLC, please delete the first paragraph in the entirety and replace with the following:

Jackson National Asset Management, LLC ('JNAM'), located at 225 West Wacker Drive, Chicago, Illinois 60606, makes the allocations to JNL Multi-Manager Alternative Fund, JNL Multi-Manager Emerging Markets Equity Fund, JNL Multi-Manager International Small Cap Fund, JNL Multi-Manager Mid Cap Fund, JNL Multi-Manager Small Cap Growth Fund, JNL Multi-Manager Small Cap Value Fund, JNL iShares Tactical Moderate Fund, JNL iShares Tactical Moderate Growth Fund, JNL iShares Tactical Growth Fund, JNL/American Funds Moderate Growth Allocation Fund, JNL/American Funds Growth Allocation Fund, JNL/Vanguard Growth ETF Allocation Fund, JNL/Vanguard Moderate ETF Allocation Fund, JNL/Vanguard Moderate Growth ETF Allocation Fund, JNL Conservative Allocation Fund, JNL Moderate Allocation Fund, JNL Moderate Growth Allocation Fund, JNL Growth Allocation Fund, and JNL Aggressive Growth Allocation Fund. JNAM is an indirect, wholly owned subsidiary of Jackson Financial Inc. ('Jackson'), a leading provider of retirement products for industry professionals and their clients. Jackson and its affiliates offer variable, fixed and fixed index annuities designed for tax-efficient growth and distribution of retirement income for retail customers, as well as products for institutional investors. Prudential plc and Athene Life Re Ltd each hold a minority economic interest in Jackson. Prudential plc has no relation to Newark, New Jersey-based Prudential Financial Inc.

On page 247-248, in the section entitled, 'Investment Adviser, Sub-Advisers and Other Service Providers,' under 'Investment Sub-Advisers and Portfolio Managers,' for PPM America, Inc., please delete the first paragraph in the entirety and replace with the following:

PPM America, Inc. ('PPM'), which is located at 225 West Wacker Drive, Suite 1200, Chicago, Illinois 60606, serves as Sub-Adviser to the JNL/PPM America Floating Rate Income Fund, JNL/PPM America High Yield Bond Fund, and JNL/PPM America Total Return Fund. PPM, an affiliate of the Adviser, is an indirect wholly owned subsidiary of Jackson Financial Inc. ('Jackson'), a leading provider of retirement products for industry professionals and their clients. Jackson and its affiliates offer variable, fixed and fixed index annuities designed for tax-efficient growth and distribution of retirement income for retail customers, as well as products for institutional investors. Prudential plc and Athene Life Re Ltd each hold a minority economic interest in Jackson. Prudential plc has no relation to Newark, New Jersey-based Prudential Financial Inc.

On page 248, in the section entitled, 'Investment Adviser, Sub-Advisers and Other Service Providers,' under 'Portfolio Manager Compensation Structure,' for PPM America, Inc., please delete the third bulleted paragraph in the entirety and replace with the following:

•	Long-Term Incentive Programs, including PPM's Long-Term Incentive Program (LTIP), and Performance Incentive Award (PIA):

o

LTIP: For most mid- and senior level professionals, LTIP has been the primary long-term incentive program. Prior to the demerger of Prudential plc and Jackson Financial Inc. in September 2021, the program was based on PPM's overall achievement and its other US affiliates' business plan over a three-year period and had a three-year cliff vesting schedule with payments made in Prudential plc ADRs.

o

PIA: Certain senior executives, portfolio managers, analysts, and traders participate in a Performance Incentive Award (PIA) program, where PPM will invest an amount of deferred compensation in the PPM Funds, two of which have similar investment objectives and investment strategies to JNL/PPM America High Yield Bond Fund and JNL/PPM America Total Return Fund. This further aligns individual compensation to the investment performance delivered to clients. The PIA program has a three-year cliff vesting schedule. Participants in the PIA are paid in cash at the end of the vesting period.

On page 310, in the section entitled, 'Investment Adviser, Sub-Advisers and Other Service Providers,' under, 'The Distributor,' please delete the first paragraph in the entirety and replace with the following:

The Distributor. Jackson National Life Distributors LLC (the 'Distributor' or 'JNLD'), 300 Innovation Drive, Franklin, Tennessee 37067, is the statutory underwriter and facilitates the registration and distribution of shares of the Funds on a continuous basis. The Distributor is not obligated to sell any specific amount of shares. JNLD is an indirect, wholly owned subsidiary of Jackson Financial Inc. ('Jackson'), a leading provider of retirement products for industry professionals and their clients. Jackson and its affiliates offer variable, fixed and fixed index annuities designed for tax-efficient growth and distribution of retirement income for retail customers, as well as products for institutional investors. Prudential plc and Athene Life Re Ltd each hold a minority economic interest in Jackson. Prudential plc has no relation to Newark, New Jersey-based Prudential Financial Inc.

This Supplement is dated September 14, 2021.