The decline is likely the result of consumers spending less on nonessential products due to global shelter-in-place orders and the economic uncertainty brought on by the pandemic, the firm said.
"The coronavirus pandemic caused the global smartphone market to experience its worst decline ever," said Anshul Gupta, senior research analyst at Gartner. "Most of the leading Chinese manufacturers and Apple were severely impacted by the temporary closures of their factories in China and reduced consumer spending due to the global shelter-in-place."
The world's top smartphone vendors -- Samsung, Huawei and Apple -- all recorded a drop in first-quarter sales, though Samsung managed to hold onto its No. 1 spot in the market. Gartner said the company managed to prevent a steeper decline in part because of its "limited presence in China."
Gartner forecasted last week that shipments of devices such as PCs, tablets and mobile phones will decline 13.6% globally this year as a result of the pandemic. Gartner predicts that mobile phone shipments alone will drop by 14.6% as customers extend the life of their phones to reduce nonessential spending.