Currently, Wal-Mart operates a slew of more than 20 smaller office buildings throughout the state. But McMillon said that has become "expensive and inefficient to maintain."
Also, the dispersed offices "literally encouraged us to work in silos," he said.
The big-box retailer said it intends to bring most of its home office associates in northwest Arkansas onto the new campus, which will include improved parking, meal services and fitness opportunities. The improvements are aimed at helping to attract "high-quality talent" by making the campus a more appealing place to work.
Also, by having everyone together, McMillon anticipates more collaboration and agile decision-making.
Wal-Mart said it expects the construction process to take five to seven years to finish, with the work being done in phases. The retailer said it will be incorporating the costs into its annual budgeting process.
Wal-Mart's current home office, built in 1971, is located at the corner of SW 8th Street and Walton Boulevard in Bentonville. The new space will be built along J Street.
"There's still a tremendous amount of planning, design and coordination to be done," McMillon said.
— CNBC's Courtney Reagan contributed to this reporting.