The former Scottish Socialist Party leader, who was jailed in 2011 for perjury relating to his legal action against the News of the World newspaper, said on Twitter that he “looked forward to working alongside others” in the promotion of Scottish independence.
Mr Salmond announced the creation of the party on Friday, where he said he would field list MSPs in the May Holyrood elections. Prominent politicians due to stand include former justice secretary Kenny MacAskill and MP Neale Hanvey.
Mr Sheridan had been due to stand for AfI - formerly known as Action for Independence, which withdrew all of its candidates just hours after announcing them following the news of the formation of Alba It is not clear on whether he is likely to stand for election for Alba.
Mr Sheridan said: “Both my wife Gail & I have joined the new progressive pro-independence party Alba. We look forward to working alongside others in the promotion of the positive & urgent case for Scottish independence. We must deliver the Indy Supermajority in 5 weeks time so it's SNP 1/Alba 2.”
Sheridan sued the News of the World for defamation after the paper published a story in 2004 alleging that he had cheated on his wife Gail with a woman called Fiona McGuire.
In 2006, a jury awarded him £200,000 after Sheridan described how the claims made by Ms McGuire detrimentally affected his reputation of being a family man. The paper claimed that he was an adulterer who attended a swingers club. Sheridan denied ever doing these things. However, in December 2010, Sheridan was convicted at the High Court in Glasgow of committing perjury during the defamation proceedings.
Other politicians to join Mr Salmond include Chris McEleny, a former group leader of the SNP on Inverclyde council. On announcement of his decision, Mr McEleny stated that he believes the former first minister “is a man of integrity”.
Mr Salmond has claimed that a vote for his party would allow those who previously voted for the SNP on the both ballots to vote for a party committed to independence and more likely to return MSPs via the regional list.
Both Alba and Mr Sheridan have been contacted for comment.