The $16 billion transaction includes $2 billion in assumed debt.
Beam's brands include Jim Beam, Maker's Mark, Sauza, Canadian Club and Courvoisier.
Suntory will pay $83.50 per share in cash, a 25 percent premium to Beam's closing share price of $66.97 on Friday.
Bottles of Jim Beam Maple bourbon move down the bottling line at the Beam distillery in Clermont, Kentucky.Luke Sharrett | Bloomberg | Getty Images
The transaction, which has been unanimously approved by each company's board of directors, is expected to close in the second quarter of 2014, subject to Beam stockholders' approval, regulatory approvals and other customary closing conditions.
Shares of Beam shot higher in pre-market trading.
–By Reuters. CNBC.com contributed to this article.