Angus McNeil said the Northern Lighthouse Board (NBL) was open to the idea of working with the mobile phone service providers.
He said it was possible equipment needed to provide the phone services could be fitted to lighthouses.
The SNP MP for the Western Isles hopes to progress the idea further.
Mr MacNeil contacted NLB following a query from phone company EE on the use of lighthouse sites which could allow them to improve coverage.
He said: "NLB have said that they are committed to developing the Scottish economy and are therefore open to discussions with mobile providers on where opportunities might lie.
"I would like to thank NLB for their prompt, sensible response and their ability to see the bigger picture."
Mr MacNeil added: "I have already received confirmation from Vodafone that 4G will be delivered to the islands within the next two years but the sooner all companies have infrastructure in place to do this, the better for the economy of the islands.
"I look forward to further discussions with operators and NLB on how we can take this forward."
Lighthouses could help improve mobile phone coverage in the Western Isles and boost the introduction of new 4G services to the isles, an MP has said.