Investors looking for safe dividend stocks want the dividend to be sustainable and offer a reasonable yield. Both factors require companies to have solid business models that can generate significant cash flow year in and year out. Three companies especially meet these criteria:

Company

Market Cap

Dividend Yield

Johnson & Johnson (NYSE:JNJ)

 $354 billion  2.55%

The Procter & Gamble Company (NYSE:PG)

 $225 billion  3.13%

United Parcel Service, Inc. (NYSE:UPS)

 $94 billion  3.10%

Data source: Yahoo! Finance.

All three of these companies pay dividends that investors should be able to count on for years to come. Here's why Johnson & Johnson, Procter & Gamble, and United Parcel Service rank as three of the top safe dividend stocks on the market.

"Dividends" is written on a scrap of paper held up by a twig, next to a roll of money.

Image source: Getty Images.

Johnson & Johnson

Johnson & Johnson, the world's largest healthcare company, is organized into three business segments: consumer, medical devices, and pharmaceutical. Its consumer segment markets a wide range of products, including Band-Aid bandages and Tylenol pain medication. The medical-devices segment sells orthopedic, surgery, cardiovascular, diabetes care, and vision-care devices. The pharmaceutical segment develops and markets leading prescription medications, including autoimmune-disease drug Stelara and diabetes drug Invokana.

Investors have turned to Johnson & Johnson as a safe dividend haven for a long time. The company is a member of the elite group of dividend aristocrats and has increased its dividend for 54 consecutive years.

Although the healthcare area is highly competitive, J&J's product depth, broad scope, and financial resources should allow the company to remain a leader well into the future. It's likely that the pharmaceutical segment will continue to increase in importance to the company's bottom line. With one of the best drug pipelines among big pharma companies, Johnson & Johnson appears to be in great shape for sustained success.

Procter & Gamble

Procter & Gamble is the world's second-largest consumer-goods company. It's organized into five business segments: beauty, grooming, healthcare, fabric and home care, and baby, feminine, and family care. P&G's well-known brand names include top-selling products such as Pantene shampoo, Gillette razors, Crest toothpaste, Tide detergent, and Pampers diapers.

Like Johnson & Johnson, Procter & Gamble is a member of the dividend aristocrats. The company has paid a dividend for an astounding 127 consecutive years and has increased its dividend for the past 61 years.

The sustainability of Procter & Gamble's dividend appears to be rock solid. Because P&G markets the types of products customers will always need, and because its brands have excellent name recognition and are widely trusted, the stock is much less volatile than most stocks, as P&G's low beta of 0.55 bears out.

United Parcel Service

United Parcel Service is the world's largest package delivery company. It has three business segments: U.S. domestic package, international package, and supply chain and freight. Last year, the company delivered an average of 19.1 million packages per day, or a total of 4.9 billion. 

Although UPS isn't a dividend aristocrat like J&J and P&G, it can still claim a good dividend track record. Since initiating its dividend program in 2000, the company has increased its dividend 14 out of the past 16 years.

Increasing use of e-commerce continues to drive growth for UPS. The company enjoys a nice protective moat, since building out an international delivery operation would require an enormous investment that few companies could afford. Although some wonder how UPS might be affected by the efforts of large internet retailer Amazon.com (NASDAQ:AMZN) to develop its own drone-based delivery service, UPS seems likely to thrive regardless of what Amazon does.

Keith Speights has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Amazon and Johnson & Johnson. The Motley Fool has a disclosure policy.