Loretta Johnson is the secretary-treasurer of the American Federation of Teachers, AFL-CIO. She was elected to the position July 2011. Before becoming AFT secretary-treasurer, Johnson was the union's executive vice president (2008 to 2011).

Also in 2011, Johnson was elected treasurer of the AFT Educational Foundation and chair of the AFT Benefit Trust. She also serves on the board of directors of the Albert Shanker Institute.

Johnson was an AFT vice president for 30 years, and she chaired the AFT Paraprofessionals and School-Related Personnel program and policy council for 32 years. She also served as president of the Baltimore Teachers Union's paraprofessional chapter for 35 years and as president of AFT-Maryland for 17 years.

In 2014, Johnson chaired the AFT Racial Equity Task Force, leading the AFT to become the first public sector union in modern history to issue a substantive, action-oriented report on achieving racial equity in America, "Reclaiming the Promise of Racial Equity in Education, Economics and Our Criminal Justice System."

Johnson started her career in 1966 as a teacher's aide in a Baltimore elementary school, where she earned $2.25 an hour and received no benefits. To improve the work situation of paraprofessionals like herself, she organized them into the Baltimore Teachers Union. In 1970, she negotiated the union's first contract, which was especially notable for its grievance procedure. That experience laid the foundation for Johnson's union activism. Her efforts have helped the BTU become a lobbying and political force in City Hall, the Baltimore community and the Maryland state Legislature. Over the years, she has served as chief negotiator for many other teacher and paraprofessional contracts as well.

Johnson has held, and currently holds, several leadership positions outside the AFT. She is a vice president of the AFL-CIO — the federation representing 55 national and international unions, including the AFT — and serves on the boards of the AFL-CIO's Transportation Trades Department, Union Label and Service Trades Department, and Union Privilege organization. She was vice president of the Metropolitan Baltimore Council AFL-CIO for 30 years, and is a trustee for the Maryland State and District of Columbia AFL-CIO. She also serves on the board of directors of the Municipal Employees Credit Union of Baltimore. Johnson was named treasurer of the national board of the A. Philip Randolph Institute in 2008, and is president of APRI's Baltimore chapter. She is the assistant treasurer for the Baltimore County chapter of the NAACP. In addition, she is on the boards of the BlueGreen Alliance, Citizens for Tax Justice, the Child Labor Coalition (which she co-chairs), the Faith & Politics Institute, and the Institute for Women's Policy Research (which she chairs).

In 2015, Johnson was named corporate representative to the National Alliance of Black School Educators. She also serves on American Income Life Insurance Company's Labor Advisory Board, Master Your Card's African American Advisory Board, and Community Engagement in the State Courts' Advisory Board.

Johnson's political activism led her to receive the 2018 Economy/Labor Service Award from the Baltimore County Democratic Party. She was also honored as 2005 Labor Leader of the Year by the Maryland Democratic Party. Ebony magazine also featured her in an article titled "Blacks of Influence in Unions."

Johnson earned her teaching degree through the Career Opportunities Program at Coppin State University in Maryland. She has received numerous honors and awards, including an honorary doctorate from Coppin State, a community service award from the United Way, and a volunteer service award from the Maryland State AFL-CIO. She also received the Albert Shanker PSRP Pioneer Award and a service award from the Baltimore Teachers Union's paraprofessional chapter.

Johnson is the proud mother of three children, whom she raised with her late husband, Leonard. She has seven grandchildren and seven great-grandchildren.