A Lincoln Day Dinner (sometimes called Lincoln Dinner) is an annual celebration of the Republican Party and a fundraising event for Republican Party affiliated organizations at the county level. Traditionally, it is held in February or March depending on the county, and sometimes on Lincoln's Birthday (February 12), although it can be held on any day. It will generally feature a notable person as a speaker. Its counterpart for the Democratic Party is the annual Jefferson–Jackson Dinner.

The event is named after Abraham Lincoln, the first elected president of the Republican Party who helped found and shape the party, and is famous for having issued the Emancipation Proclamation which freed slaves held in rebellious Southern states. Subsequent to the election of Ronald Reagan (1980), the most popular Republican president since Lincoln, some counties renamed the dinner after Reagan or have added his name to it, resulting in the names Reagan Dinner, Reagan Day Dinner, Lincoln–Reagan Dinner, etc. In particular, this trend is common in the Southern United States.^[1]