Reiner had refused for weeks to resign as chairman of the First 5 California Children and Families Commission, after it as revealed he used $23 million in commission funds for advertising on behalf of a ballot initiative to create universal preschool in California.
Gov. Arnold Schwarzenegger issued a statement praising Reiner's work on the commission.
"Rob Reiner has always put California's kids first and I thank him for the great work he has done over the last seven years," Schwarzenegger said.
Republican state senators had accused Reiner of abusing his position to promote the preschool ballot initiative. Reiner took a temporary leave as commission chairman last month as he campaigned for Proposition 82 -- which would raise income taxes on wealthy Californians by $2.4 billion to fund preschool for all 4-year-olds in California.
A state audit is under way to determine whether there was any connection between the Yes on 82 campaign and the tax-funded ad blitz promoting preschool, The Los Angeles Times reported.