Barclay was born in Chicago Heights, Illinois. He attended La Lumiere School, a private college preparatory boarding school in La Porte, Indiana. On scholarship, he was one of the first African-Americans to attend the school, Barclay went on to Harvard College, where he was extremely active in student musical theatre productions and the a cappella singing group The Harvard Krokodiloes.

In June 2013, Paris was elected President of the Directors Guild of America, the first African-American and first openly gay President in the history of the Guild . After the vote, Barclay expressed gratitude for the honor and admiration for the Union's history, saying "I am profoundly honored to be elected President of the DGA.... The DGA has worked for more than three-quarters of a century to advance the creative and economic rights of directors and their teams and I look forward to continuing this strong tradition of service. As the son of a glass blower and a tile maker from Chicago, I am extremely humbled to have the honor to serve in the footsteps of the legendary leaders of the DGA like Frank Capra, Robert Wise and Gil Cates." Barclay was nominated for the Presidency by past-President Michael Apted, who said of him, "Paris' qualifications for DGA president are exceptional.... His understanding of the issues facing directors and their teams is outstanding and his ability to resolve problems and create solutions is beyond compare." His nomination was seconded by Steven Soderbergh, who said of Barclay, "This is a great moment for our Guild; Paris will be a phenomenal leader as we move into the future." Paris was enthusiastically re-elected in June 2015 to continue his notable presidency.  Before being elected DGA President, Barclay served four terms as First Vice President of the DGA, where he was the first African-American Officer in the history of the guild. While serving as First Vice President, Paris was also chair of the DGA's Political Action Committee, whose mission it is to promote the interests of DGA members to state and federal lawmakers. Their top issues include battling online copyright threats and promoting production tax incentives. He also served on the Western Directors Council and co-chaired the Diversity Task Force, whose mission is to encourage the hiring of women and minority directors to networks and studios. In addition, Paris served as a board member of the DGA-affiliated Franco-American Cultural Fund, which promotes cultural exchange between French and American directors.  Barclay completed his second term as DGA president in June 2017. He was succeeded by Thomas Schlamme, whom he worked with on The West Wing and Manhattan, as well as on the DGA board.

Did they ever hire any woman in the guild of America?