AllianceBernstein L.P. (AB) is a global asset management firm providing investment management and research services worldwide to institutional, high-net-worth and retail investors.

AllianceBernstein is based in New York City, U.S.. It has approximately US$498 billion in assets under management as of June 30, 2017. It is 64 percent owned by the French insurance conglomerate, AXA.

AllianceBernstein traces its origins back to the founding of Sanford C. Bernstein in 1967 as an investment-management firm for private clients. Sanford C. Bernstein & Company was originally co-founded by Zalman Bernstein, Paul P. Bernstein, Shepard D. Osherow, Roger Hertog and Lewis Sanders.

Alliance Capital was founded in 1971 when the investment-management department of Donaldson, Lufkin & Jenrette, Inc., merged with the investment-advisory business of Moody's Investor Services, Inc.

In October 2000, Alliance Capital acquired Sanford C. Bernstein. Alliance Capital's growth equity and corporate fixed-income investing, and its family of retail mutual funds, accompanied Bernstein's value equity and tax-exempt fixed-income management, and its private-client business.

It had about US$800 billion assets under management as of the end of 2007.

On January 20, 2015, AllianceBernstein announced a new brand name, "AB" and logo.

AllianceBernstein provides investment services and solutions for institutions across the globe. Typical clients include Defined benefit pension plans and Defined contribution plans. As of December 31, 2014 Institutional Assets under management were US$237 Billion.

The retail part of AllianceBernstein provides financial professionals and individual investors with the investment solutions, research, insights and tools that cover mutual funds, Managed Accounts, College Saving, Retirement Saving, and Insurance Services.

Sell-side research and brokerage services are provided by wholly owned subsidiary Sanford C. Bernstein. It is also well known as Bernstein Research.

Bernstein Wealth Management, part of AllianceBernstein, provides investment and wealth-planning services for high-net-worth clients in the Americas

Rhode Island’s 529 savings plan, CollegeBoundfund®, was managed by AllianceBernstein and featured AllianceBernstein mutual funds until 2016. It is now administered by Ascensus College Savings.

AllianceBernstein's global headquarters are located in New York City at 1345 Avenue of the Americas. AllianceBernstein has offices in 46 locations across 22 countries.

According to Form 8-K report, as of Jan 29, 2015, the French Insurance and Investment Bank AXA owned an approximate 62.7% economic interest in AllianceBernstein.