The company said the change is in addition to wage increases already planned for many USA markets in the coming fiscal year.
Walmart raised its minimum wage to $9 an hour in 2015 and the following year offered a $1 rise to those who completed an internal training scheme.
Issuing one time bonuses has been a popular response after US President Donald Trump signed his party's new tax plan into law.
Walmart is likely to save billions of dollars from the new tax law, which slashed the corporate tax rate to 21% from 35%, and the wage hikes will cost the retailer only a fraction of those gains, analysts said. They do also reflect the tight labor market in which employers are competing for workers, as both Walmart and its rival Target have been raising wages for the past few years. The company is also creating a new benefit to assist associates with adoption expenses. The amount of the bonus will vary based on length of service, reaching up to $1,000 for an individual with 20 years of service.
It is the latest in a line of United States giants that have promised to pass on some of the cash unleashed to staff. Others, including Wells Fargo and AT&T have promised wage rises or bonuses.
The pay increase, Wal-Mart's third minimum wage increase since 2015, and bonus will benefit more than 1 million USA hourly workers, it said. As of December, the average pay for full-time workers was $13 an hour.
Wal-Mart employs about 2.2 million people globally, with more than 1.5 million in the U.S. and had total global revenue of almost $500 billion a year ago.
McMillon said Walmart is in the "early" stages of assessing opportunities from the GOP tax plan, adding "tax reform gives us the opportunity to be more competitive globally and to accelerate plans for the U.S". The company said its new wage hike will be effective for the February 17 pay cycle.
Walmart also announced expansion of its paternal and maternity leave policy, providing full-time hourly employees with 6 weeks of paid paternal leave and 10 weeks of paid maternity leave.