Humane Society Legislative Fund (HSLF) is an animal rights advocacy organization formed in 2004, as the 501(c)(4) lobbying arm of the Humane Society of the United States (HSUS) and the Fund for Animals. The Doris Day Animal League joined the Fund in 2006. 
HSLF was formed to pass animal protection and vegetarian-interest laws on both state and federal levels, educate the public about animal liberation issues, train political activists, and support candidates for office. 
HSLF focuses its legislative lobbying work on issues such as animals in research, prevention of cruelty to pets, and protections for farm animals, horses, and wildlife. 
HSLF endorses and makes campaign contributions to candidates that it ranks highly for supporting its agenda. 
The Humane Society Legislative Fund currently supports legislation intended to protect animals, such as the Big Cat Safety Act, the Humane Cosmetics Act, the Horseracing Integrity Act, among many others. 
On May 4, 2020, HSLF, along with other left-of-center vegetarian-interest and environmentalist groups like Farm Sanctuary, Mercy for Animals, and Center for Biological Diversity, submitted a letter to Congressional leaders demanding the slowdown of production at slaughterhouses. 
HSLF gives a state-by-state list of endorsements for the 2020 election cycle, which it claims are exclusively based on a candidate’s “records or positions on animal welfare issues,” and does not take into account a candidate’s party affiliation. It mostly endorses Democratic candidates. 
HSLF keeps a scorecard for members of Congress, grading each legislator’s record on animal protection. HSLF goes on to highlight its highest and lowest scorers, denoting each legislator’s political party affiliation. An overwhelming majority of the highest scorers are Democrats, while the lowest scorers, called “Total Zeroes” are almost exclusively Republicans. 
HSLF contributes to the federal candidates it favors, and has contributed over $160,000 in 2020 elections as of early May, mostly to Democratic candidates. It provided $5,000 to Rep. Tony Cardenas (D-CA), $6,250 to Rep. Earl Blumenauer (D-OR), and $6,500 to Sen. Martha McSally (R-AZ), all of who scored more than 100 on HSLF’s scorecard.  In years past, HSLF has made even larger campaign contributions, including $360,500 in 2018, $444,500 in 2016, and $301,000 in 2014, predominantly supporting Democrats.
Sara Amundson is the president of the Humane Society Legislative Fund, managing political and legislative activity for the organization. Amundson also serves as the treasurer of the Humane Society Legislative Fund PAC. 
Board of Directors
Bernard Unti serves as assistant treasurer of the Board. Unti is the senior policy advisor and special assistant to the president and CEO of HSUS, and has held positions with other HSUS-affiliated groups including Humane Society International, Humane Society University (HSU), and Humane Society Institute for Science and Policy (HSISP). 
Charles A. Laue is the chair of the board, and also sits on the board of Humane Society of the United States (HSUS). Laue is the co-founder and Chairman of Stray Dog Capital, and serves as the chair of the Great Plains SPCA. 
David Robb is the vice chair of the board and sits on the HSUS North Carolina State Council and the board of the North Carolina Zoological Society.  2020. Thomas Waite III serves as treasurer of the board of both HSLF and the Humane Society International. 
Michaelen Barsness is the assistant treasurer of the boards of both HSLF and Humane Society International. Barsness is the vice president of finance and controller at HSUS, and the former vice president and controller at the United Way Worldwide.  Barsness is the treasurer of the board of the Fund for Animals. 
Susan Atherton serves on the boards of both HSLF and the Humane Society International.  Atherton serves as the vice chair of the boards of both the Humane Society Legislative Fund, and the San Francisco SPCA. Atherton formerly served as chair of the board of the American Red Cross Bay Area.