A surge in the firm's share price has taken its market capitalisation to $373bn (£285bn), racing past the supermarket's $370bn.
Tesla's stock passed the $2,000 mark on Thursday, ahead of its planned shares split which will see investors receive five shares for every one they hold.
Some analysts predict Musk's company will become one of the largest firms in the world, according to the Daily Mail.
The firm is storming past traditional car makers due to its cutting-edge battery technology with its shares seeing a 806% rise in just 12 months.
But Walmart still remains a much larger company, maintaining its position as the world's largest retailer. The supermarket giant has annual revenues of $524bn and profits of $15bn, compared to Tesla's revenues of $24.6bn and profit of $35.8m in 2019.
It also employs 2.2 million people across 11,500 global stores compared to Tesla's 50,000 workforce with 200 shop fronts.
But Tesla has recently expanded into China, establishing a factory in Shanghai.
Tim Bain, president at investment group Spark Asset Management, said investors needed to consider whether Tesla would move beyond being just a car company.
"In order to justify a valuation that can continue to grow at above-market rates, investing in Tesla today requires you to believe that they will move into energy production and storage," he said earlier this month.