The automaker gave no explanation why Smith, 49, was resigning after 26 years with the firm -- but it came after unions and company chiefs failed to reach agreement in talks last week.
Jaguar Land Rover wants to make changes to pay and pensions for new employees but has come up against union resistance.
The company, however, insisted the negotiations were not linked to Smith's resignation.
"We are disappointed the discussions ended without agreement, but his departure is not linked to the talks," said a spokesman.
The firm also pointed out Smith had been in charge in June 2008, when the group was acquired by India's Tata Motors for $2.3 billion (1.6 billion euros, 1.4 billion pounds).
"The company would like to thank David for his efforts in the role and for his service to Jaguar and Land Rover over many years," said the firm.
The group said its director Ravi Kant would temporarily take over Smith's duties until a permanent replacement is found.
Keep up with the latest business news from the region with the Emirates Business 24|7 daily newsletter. To subscribe to the newsletter, please click here.