Rolling out now and sporting the brand's signature red livery on foil packaging, the newcomer joins full sugar flavour variants Peppermint and Spearmint.
Roche claimed trials in selected stores last year showed sugar free presented a huge sales opportunity for the sector.
"Sales were good, even though, at £1.89, Rennie Sugar Free is positioned at a price premium compared to original Rennie," explained Pam Kemp, OTC category manager.
"Many consumers opt for sugar-free alternatives in their day-to-day lives such as soft drinks, chewing gum and mints," she added.
"We want to offer them the same choice when they select an indigestion remedy."