Exhibit 99.1

RLI Reports 2012 Fourth Quarter and Year-End Results

PEORIA, ILLINOIS, January 23, 2013 — RLI Corp. (NYSE: RLI) — RLI Corp. reported fourth quarter 2012 operating earnings of $19.2 million ($0.89 per share), compared to $28.2 million ($1.31 per share) for the fourth quarter of 2011. For the year ended December 31, 2012, operating earnings were $86.9 million ($4.02 per share) compared to $115.5 million ($5.39 per share) for the 2011 fiscal year.

*2011 results were revised to reflect the retrospective adoption of a new accounting standard for policy acquisition costs.

(1) See discussion of non-GAAP financial measures on page 3.

Highlights for the quarter included:

·                  11% growth in gross premiums written.

·                  Underwriting income of $8.5 million, resulting in a combined ratio of 94.3.

·                  $7.5 million net increase in underwriting income resulting from favorable development on prior years’ loss reserves.

·                  $13.2 million net decrease in underwriting income resulting from Hurricane Sandy.

·                  Special dividend of $5.00 per share, representing $106.3 million returned to shareholders and resulting in a tax benefit of $2.9 million as dividends to the ESOP are fully deductible.

·                  $6.6 million dividend from Maui Jim, Inc. resulting in a tax benefit on dividends received from affiliates of $1.8 million.

Highlights for the year included:

·                  12% growth in gross premiums written.

·                  Underwriting income of $63.6 million, resulting in a combined ratio of 89.0.

·                  17th consecutive year of underwriting income.

·                  Book value per share of $37.45 at year end, representing an increase of 17%, inclusive of dividends.

·                  $59.8 million net increase in underwriting income resulting from favorable development on prior years’ loss reserves.

·                  $30.8 million net decrease in underwriting income resulting from catastrophe events including Hurricane Sandy.

·                  Comprehensive earnings of $129.2 million ($5.99 per share).

“We delivered solid financial results during the fourth quarter,” said RLI Corp. Chairman & CEO Jonathan E. Michael. “We achieved good top line growth and reported a 94.3 combined ratio, despite the impact of Hurricane Sandy.”

“I am also pleased to report favorable underwriting results for the year, particularly in light of increased natural catastrophe events that occurred in the U.S.,” said Michael. “Throughout 2012, we remained focused on disciplined underwriting and execution. We expanded our product portfolio through new business initiatives including the acquisition of Rockbridge Underwriting, the addition of a recreational vehicle insurance product and other initiatives. Our collective efforts during the year resulted in an 89 combined ratio. In addition, we were able to reward our shareholders by returning $106.3 million through a special dividend.”

“Our performance can be attributed to the expertise and dedication of our talented employees. Their hard work has positioned RLI for future growth and will allow us to take advantage of new opportunities created by improving market conditions,” said Michael.

—more—

Underwriting income

RLI achieved $8.5 million of underwriting income in the fourth quarter of 2012 on a 94.3 combined ratio, compared to $25.6 million of underwriting income on an 82.3 combined ratio in the same quarter for 2011. The quarter was impacted by hurricane losses with a $13.2 million net decrease in underwriting income due to Hurricane Sandy.

For the year, RLI achieved $63.6 million of underwriting income on an 89.0 combined ratio, compared to $110.2 million of underwriting income on a 79.6 combined ratio in 2011. Results for 2012 include $59.8 million in favorable development in prior years’ loss reserves, compared to $91.7 million in favorable development in prior years’ loss reserves in 2011.

The following table highlights annual underwriting income and combined ratios by segment:

*2011 results were revised to reflect the retrospective adoption of a new accounting standard for policy acquisition costs.

Other income

RLI’s net investment income for the quarter declined 10.8% to $14.5 million, compared to the same period in 2011. For the year ended December 31, 2012, investment income was $58.8 million versus $63.7 million for the 2011 fiscal year. The decline in investment income was due to lower reinvestment rates as well as higher allocation to tax-exempt municipal bonds, which have lower pre-tax yields than taxable alternatives. The investment portfolio’s total return was 0.4% for the quarter. The bond portfolio returned 0.7% in the quarter, and the equity portfolio’s return was -0.8%. For the year ended December 31, 2012, the investment portfolio’s total return was 7.5% with the bond portfolio returning 6.4% and equities returning 11.5%.

Comprehensive earnings, which include after-tax unrealized gains/losses from the investment portfolio, were $13.2 million for the quarter ($0.61 per share) compared to $57.6 million ($2.68 per share) for the same quarter in 2011. Full-year comprehensive earnings were $129.2 million ($5.99 per share), compared to $147.9 million ($6.90 per share) in 2011.

During the quarter, equity in loss of unconsolidated investee was $0.1 million compared to a loss of $0.7 million from the same period last year, both of which reflect seasonal results. These results are related to Maui Jim, Inc., a producer of premium sunglasses. For the year ended December 31, 2012, equity in earnings of unconsolidated investee was $8.9 million, a 36% increase compared to 2011. During the quarter, RLI received a $6.6 million dividend from Maui Jim, Inc., which resulted in a tax benefit on dividends received from affiliates of $1.8 million ($0.09 per share).

Special and regular dividends

On December 20, 2012, RLI paid an extraordinary cash dividend of $5.00 per share, which totaled $106.3 million, and a regular quarterly dividend of $0.32 per share, which totaled $6.8 million. RLI has paid dividends for 146 consecutive quarters and increased regular dividends in each of the last 37 years. The company’s regular quarterly dividend has grown an average of 13.8% over the last 10 years.

Recently adopted accounting standard

As previously disclosed in RLI’s Annual Report on Form 10-K for the year ended December 31, 2011, subsequent 10-Q Quarterly Reports, and the Form 8-K Current Report filed on December 17, 2012, accounting guidance for deferred acquisition costs incurred by insurance entities changed in 2012 under ASU 2010-26, Financial Services — Insurance (Topic 944) Accounting for Costs Associated with Acquiring or Renewing Insurance Contracts. Prior period amounts have been presented on a comparative basis.

2

Non-GAAP measures

Underwriting income, operating earnings, earnings per share (EPS) from operations and other per share items are non-GAAP financial measures, and we believe that investors’ understanding of RLI’s core operating performance is enhanced by our disclosure of these financial measures. Underwriting income or profit represents the pretax profitability of our insurance operations and is derived by subtracting losses and settlement expenses, policy acquisition costs, and insurance operating expenses from net premium earned. Operating earnings and EPS from operations consist of our net earnings adjusted by net realized investment gains/(losses) and taxes related to net realized gains/(losses). Our definitions of these items may not be comparable to the definitions used by other companies. Net earnings and net earnings per share are the GAAP financial measures that are most directly comparable to operating earnings and EPS from operations. All earnings per share data are calculated using fully diluted shares. Combined ratio refers to a GAAP combined ratio.

Other news

At 10 a.m. central time (CT) tomorrow, January 24, 2013, RLI management will hold a conference call to discuss quarterly results with insurance industry analysts. Interested parties may listen to the discussion through the Internet at www.rlicorp.com.

Except for historical information, this news release may include forward-looking statements (within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934) including, without limitation, statements reflecting our current expectations about the future performance of our company or our business segments or about future market conditions. These statements are subject to certain risk factors that could cause actual results to differ materially. Various risk factors that could affect future results are listed in the company’s filings with the Securities and Exchange Commission; including the Form 10-K Annual Report for the year ended December 31, 2011.

RLI, a specialty insurance company, offers a diversified portfolio of property and casualty coverages and surety bonds serving niche or underserved markets. RLI operates in all 50 states from office locations across the country. RLI’s insurance subsidiaries — RLI Insurance Company, Mt. Hawley Insurance Company, RLI Indemnity Company and Contractors Bonding and Insurance Company — are rated A+ “Superior” by A.M. Best Company.

For additional information, contact Aaron Jacoby, Vice President, Corporate Development at 309-693-5880 or at aaron.jacoby@rlicorp.com or visit our website at www.rlicorp.com.

3

Supplemental disclosure regarding the earnings impact of specific items:

(1)    2011 results revised due to the retrospective adoption of a new accounting standard for policy acquisition costs.

(2)    Includes bonus and profit sharing-related impacts which affected other insurance and general corporate expenses.

(3)    Reserve development reflects changes from previously estimated losses.

(4)    Dividends paid in an ESOP on employer securities are fully deductible from taxable income and result in a 35% tax benefit.

(5)    As required under the accounting standard for income taxes, the gain reflects the tax benefit of applying the lower tax rate applicable to dividends received from an affiliate (7%) as compared to the corporate capital gains tax rate (35%) on which tax estimates were based.

4

RLI CORP.

2012 FINANCIAL HIGHLIGHTS

(Unaudited)

(Dollars in thousands, except per share amounts)

(1)  Revised due to the retrospective adoption of a new accounting standard for policy acquisition costs.

(2)  See discussion of non-GAAP financial measures on page 3.

5

RLI CORP.

2012 FINANCIAL HIGHLIGHTS

(Unaudited)

(Dollars in thousands, except per share amounts)

(1)  Revised due to the retrospective adoption of a new accounting standard for policy acquisition costs.

6

RLI CORP.

2012 FINANCIAL HIGHLIGHTS

UNDERWRITING SEGMENT DATA

(Unaudited)

(Dollars in thousands, except per share amounts)

Three Months Ended December 31,

Twelve Months Ended December 31,

(1)  Revised due to the retrospective adoption of a new accounting standard for policy acquisition costs.

7