The free initiative is being tested in Kenya in a 3-month trial in cooperation with Indian mobile provider Airtel, Wikipedia said.
"Throughout most of the developing world, data-enabled smartphones are the exception, not the rule," Dan Foy, technical partner manager for the Wikimedia Foundation, wrote in a posting.
"That means billions of people currently cannot see Wikipedia on their phones."
Users who to dial *515# can activate the service, dubbed Wikipedia Zero, and search for articles, which will be sent to the user's phone in message-sized portions.
Tom Jakcson, the editor of African technology news website HumanIPO hailed Wikipedia's initiative as a welcomed effort.
"There has been a steady move towards putting educational material online in many African countries, led mainly by the private sector rather than governments, but access to the Internet remains a problem given that most Africans surf on their phones rather than browsers," Jackson told the BBC.
"This step increases the chances of access, especially as there is functionality to provide Wikipedia via SMS," he said. "Feature phones are still dominant in Africa, so this is a helpful addition."