The chain will be removing the chicken broth and animal-based seasonings from its Eggplant Tofu and Chow Mein dishes, according to campaign group Vegan Outreach.
The move follows a campaign by Animal Outreach, which garnered almost 5,000 signatures on a petition calling for vegan dishes.
"While seemingly small, this change by Panda Express will make a big impact. Not only will the chain contribute less to animal suffering by using more plant-based ingredients, but it will send a powerful message to other chains - this is financially beneficial and if we can do it, so can you.
"Both menu items will be vegan by the end of February, but we recommend checking with your local store before you order them."
The chain follows a slew of other major north American outlets which have added plant-based dishes to their menus in a bid to cater to growing numbers of vegans, vegetarians, and flexitarians, including Carl's Jr., Taco Bell, TGI Fridays, and A&W.
Vegan is mainstream
The US hospitality sector follows the retail sector in seeing a surge when it comes to demand for plant-based alternatives, with leading business and food expert and Executive Director of the Plant Based Foods Association (PBFA) Michele Simon branding vegan food 'fully mainstream'.
Data from Nielson, published last year, showed the plant-based foods industry experienced dollar sales growth of 20 percent between 2017 and 2018, with sales topping $3.3 billion.
Talking about the data, Simon said: "The plant-based foods industry has gone from being a relatively niche market to fully mainstream.
"Plant-based meat and dairy alternatives are not just for vegetarians or vegans anymore; now even mainstream consumers are enjoying these delicious and innovative options in the market today. The new data confirms what we are hearing and seeing every day from our members: sales are up, investment is increasing, and new jobs are being created in the plant-based foods industry."