Equalities minister Maria Miller said she was looking forward to the first same-sex wedding by next summer after the Bill received royal assent.
Mrs Miller said in a statement: "Marriage is the bedrock of our society and now irrespective of sexuality everyone in British society can make that commitment.
"Making marriage available to all couples demonstrates our society's respect for all individuals regardless of their sexuality.
"This is a historic moment that will resonate in many people's lives. I am proud that we have made it happen, and I look forward to the first same-sex wedding by next summer."