Michael McFaul said the ban was "because of my close affiliation with [President Barack] Obama".
Mr McFaul said he was preparing to visit Russia "to do [Hillary] Clinton transition work" before Donald Trump won the US election.
Russia's foreign ministry confirmed the ban, Russian news agencies reported.
In a public post on Facebook, Mr McFaul said: "Was told that I am on the Kremlin's sanctions list because of my close affiliation with Obama. I will take that as a compliment! The US sanctioned Russians close to Putin.
"To the best of my knowledge, George Kennan was the last US ambassador to USSR/Russia to be banned from traveling there. Good company! Hope that I am not on the Russia travel ban list forever. Since 1983, I've been living in and traveling to that country."
Mr McFaul is a professor at Stanford University and was US ambassador to Russia from 2012-14.
George Kennan, whom he mentioned, held the post in the then Soviet Union in 1952. He lost the job abruptly after comparing the conditions at the ambassador's residence in Moscow to his time under Nazi internment during World War Two.
In a series of posts on Twitter, Mr McFaul said his travel ban was probably imposed in 2014 "in response to US sanctions".
The US and the EU both heaped sanctions on Russia in 2014 after it annexed the Crimea peninsula from Ukraine. They included travel bans on senior Russian officials and the freezing of their US assets.
The European Union is likely to extend its economic sanctions against Russia in December. However, many diplomats fear President-elect Donald Trump will pursue a cosier relationship with the country that could make them harder to maintain.
Mr McFaul said he was not opposed to the mutual lifting of bans "under the right conditions".
He said he was "extremely disappointed" by the decision, adding that he had travelled to Russia hundreds of times, had many friends there and had spent most of his career studying the country.
Russia has sanctions against a number of nations, including a total ban on importing food from the EU, US, Canada, Norway and Australia.