John Rayson, a councillor of five years, and Louise Thompson, elected in 2019, stood down from their roles last week.
‘Personal reasons’ were cited for their departures.
Sidmouth Town Council chairman Ian Barlow said: “Both John and Louise brought their own unique skills to the council which benefitted many of the projects we’re are still working on.
“They put a considerable number of hours into their work as councillors on behalf of the community. Their presence in the chamber will be missed”.
Townsfolk have now been invited to request a vote to fill the vacancies.
For this to happen, ten residents in the in each of the respective electoral areas would need to ask that an election be held.
Sidmouth town clerk Christopher Holland said: “Such a request must be signed and sent to the returning officer at East Devon District Council, or sent electronically, which must include a scan of the elector’s signature, to firstname.lastname@example.org by midnight on July 2.”