Exhibit 99.1

Key Statistics:

(Data as of 06.30.15)

Total Assets (in $ millions) $6,134 Common BV/Share $22.15 Tangible BV/Share $13.65

Stock Price $29.59 Market Cap (in $ millions) $1,030 Dividend Yield (annualized) 2.43% Price/Earnings (LTM) 15.5

Profile:

S&T Bancorp, Inc. is a $6.1 billion financial holding company headquartered in Indiana, PA, located about 55 miles northeast of Pittsburgh, PA. Founded in 1902 with a single location in Indiana, PA, S&T Bancorp, Inc. has grown to 63 branch offices that provide a full range of financial services to individuals and businesses in 16 southwestern and southcentral Pennsylvania counties. Additionally, S&T has loan production offices in northeast and central Ohio, and western New York.

63 Branches in 16 Pennsylvania Counties &

Investment Thesis:

Above peer performance Strategic and effective mergers and expansion Demonstrated expense discipline and efficiency Organic growth Excellent asset quality Stable regional economy with long term oil and gas benefit

Recent Mergers and Expansions: March 23, 2015

S&T Bank loan production office opens to service western New York. March 4, 2015

S&T Bancorp merges with Integrity Bancshares in southcentral PA, adding 8 offices in 4 counties, $789 million in loans, and $722 million in deposits.

June 18, 2014

S&T Bank branch opens in State College, PA.

January 21, 2014

S&T Bank loan production office opens to service central Ohio.

Total Annualized Shareholder Return

Includes reinvested dividends (Data as of 06.30.15)

1 YR 3 YR 5 YR 10 YR STBA 22.28% 20.40% 11.65% 1.27% NASDAQ Bank 12.91% 19.83% 13.78% 1.85% KRX-Dow Jones KBW Regional Bank 15.70% 19.34% 15.81% NA S&P 500 7.42% 17.27% 17.31% 7.88%

Source: Bloomberg

Columbus

Akron

State College Pittsburgh Harrisburg

Rochester

S&T Bank Loan Production Offices

MEMBER FDIC

Senior Management: Financial Highlights:

2015 2015 2014 2013

Todd D. Brice Second Quarter First Quarter Full Year Full Year

President and Chief Executive Officer

Mark Kochvar Net Income (in $ thousands) $18,188 $12,835 $57,910 $50,539 Diluted Earnings per Share $0.52 $0.41 $1.95 $1.70 Senior Executive Vice President, Chief Financial Officer Dividends Declared per Share $0.18 $0.18 $0.68 $0.61

David G. Antolik

Senior Executive Vice President,

Total Assets (in $ millions) $6,134 $5,971 $4,965 $4,533 Chief Lending Officer Total Loans (in $ millions) $4,812 $4,690 $3,872 $3,568 David P. Ruddock Total Deposits (in $ millions) $4,859 $4,829 $3,909 $3,672 Senior Executive Vice President, Chief Operating Officer Rebecca A. Stapleton Return on Average Assets (annualized) 1.21% 0.99% 1.22% 1.12% Senior Executive Vice President, Return on Average Equity (annualized) 9.52% 7.85% 9.71% 9.21% Chief Banking Officer Return on Tangible Equity (annualized) 15.79% 11.80% 14.02% 13.94 %

Investor Relations Contact:

Net Interest Margin (FTE) (annualized) 3.67% 3.48% 3.50% 3.50%

Mark Kochvar

S&T Bancorp, Inc.

800 Philadelphia Street Nonperforming Assets/Loans + OREO 0.41% 0.41% 0.33% 0.64% Indiana, PA 15701 Allowance for Loan Losses/Total Loans 1.02% 1.03% 1.24% 1.30% 724.465.4826 mark.kochvar@stbank.net Net Loan Charge-offs (annualized) / Average Loans 0.11% 0.10% 0.00% 0.25% For more information visit stbancorp.com or stbank.com.

Common stock traded on the NASDAQ under Risk-based Capital—Total 11.48% 11.86% 14.27% 14.36% the symbol STBA

Tangible Common Equity/Tangible Assets 8.14% 8.22% 9.00% 9.03%

Analyst Coverage:

The following analysts published research about S&T Bancorp, Inc. in 2015.

Boenning & Scattergood Matthew Schultheis 610.832.5290 mschultheis@boenninginc.com Keefe, Bruyette & Woods Collyn Gilbert 973.549.4092 collyn.gilbert@kbw.com Piper Jaffray Matthew Brees 207.233.4399 matthew.m.breese@pjc.com Raymond James William Wallace 301.657.1548 william.wallace@raymondjames.com RBC Capital Markets Jake Civiello 617.725.2152 jake.civiello@rbccm.com

Our Reputation Speaks for Itself.

Named to the prestigous Sandler O’Neill Sm-All Stars Class of 2013 and 2014. Superior Customer Service

Consistently ranked high in customer satisfaction.

American Heart Association

S&T recognized as a Gold Level Fit-Friendly Worksite in 2014.

One customer at a time.

This document may contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements involve risks and uncertainties that could cause actual results to differ materially from the results discussed in these statements. These risks are detailed in the company’s latest form 10-Q and 10-K filed with the Securities and Exchange Commission.

This document also contains or references, certain non-GAAP financial measures, such as net interest margin (FTE). Although S&T believes that these measures enhance investors’ understanding of S&T’s business and performance, these non-GAAP financial measures should not be considered an alternative to GAAP, and should be read in conjunction with the audited financial statements and analysis as presented in the Annual Report on Form 10-K as well as the unaudited financial statements and analyses as presented in the respective Quarterly Reports on Forms 10-Q for S&T Bancorp, Inc. and subsidiaries.