Gabriel Bacchus Matthews (1948 – September 7, 2007) was a Liberian politician. He is considered one of the leaders in developing a multi-party system in Liberia, long dominated by the True Whig Party. He is the founder of the Progressive Alliance of Liberia (PAL) in 1975, the first legal opposition party in more than 100 years.
It was succeeded by the Progressive People Party (PPP) and later the United People's Party. Matthews twice served as Minister of Foreign Affairs of Liberia, under Samuel K. Doe (1980–1981) and later under Amos Sawyer (1990–93).
As a young man, Matthews joined the dissident movement against President William R. Tolbert. He worked to create an opposition party, as the True Whig Party had been in power for more than 100 years. In 1975 he and many among the Liberian diaspora formed the Progressive Alliance of Liberia (PAL), the first legal opposition party to be recognized in decades.
After the April 1980 coup in which Tolbert was overthrown and Samuel K. Doe came to power, Matthews was appointed as Minister of Foreign Affairs for the first time. Matthews served as Foreign Minister until 1981. He later fell out of favor with Doe, who became increasingly dictatorial.
Matthews achieved reorganization of the party as the Progressive People's Party (PPP) and legal recognition. Doe banned the party after becoming more authoritarian.
It reorganized again as United People's Party (UPP). During the 1980s, Matthews was the main opposition politician in Liberia. Roland Trobeh described him as the father of multi-party democracy in the nation.
After Doe's death, in 1990, Matthews again was appointed as Foreign Minister, serving under President Amos Sawyer. He was instrumental in bringing the ECOMOG Peacekeeping force to Liberia. He remained foreign minister until 1993, when he was replaced in a cabinet reshuffle.