An alliance is an agreement between two or more parties, made in order to advance common goals and to secure common interests.

In politics it may refer to:

• Alberta Alliance Party, right wing political party in Alberta, Canada
• Alliance, the former name of the Barisan Nasional in Malaysia
• Alliance (Iceland), political party in Iceland
• Alliance (New Zealand political party), left-wing political party in New Zealand politics
• Alliance Party of Northern Ireland, political party operating in Northern Ireland
• Canadian Alliance, Canadian right-of-centre conservative political party that existed from 2000 to 2003
• SDP-Liberal Alliance, electoral alliance of the Social Democratic Party and the Liberal Party in the United Kingdom that operated from 1981 to 1988
• The Alliance (Hong Kong), political group in Hong Kong
• United People Alliance, electoral and political coalition between the Portuguese Communist Party or PCP and the Portuguese Democratic Movement or MDP