About Mark

Mark Spreitzer (D-Beloit) is the State Senator for the 15th Senate District.

Mark is running for re-election to his second term in the State Senate after serving four terms in the State Assembly and two terms on the Beloit City Council. Mark was inspired to pursue public service by his mother, a social worker and mental health advocate, and his father, a systems analyst and bookkeeper. Mark’s parents passed along a tradition of local activism and conservation that has guided him throughout his time in public office.

Mark came to Beloit in 2005 to attend Beloit College. Mark was active in the community as a student, serving for 3 years on the City of Beloit Appointment Review Committee, including 2 years as chair. Mark graduated from Beloit College in 2009 and continued to make Rock County his home. After college, he worked for then-U.S. Senator Russ Feingold’s campaign, won a seat on the Beloit City Council in April 2011, and returned to Beloit College to work in the alumni office.

During his two terms on the City Council, Mark was elected Vice President and then President of the Council. Mark supported downtown revitalization and development in the Gateway Business Park, led the effort to extend domestic partner benefits to LGBTQ city employees, supported building a dog park, and worked to maintain affordable public transit options.

Mark was elected to the State Assembly in 2014 after Janis Ringhand vacated the seat to run for State Senate. His first bill in the State Assembly was non-partisan redistricting reform, which would end gerrymandering and put people – not politicians – in charge of drawing legislative districts. Mark authored multiple bills to improve local government operations, support beginning farmers, preserve farmland, protect our water, and combat climate change.

Mark was re-elected to the State Assembly three times and served in legislative leadership as the Democratic Caucus Chair from 2016-2022. In 2022, Mark ran for the 15th Senate District, again succeeding Janis Ringhand upon her retirement from the legislature.

Mark Spreitzer was sworn in as the State Senator for the 15th Senate District on January 3, 2023. In November 2024, Mark was elected by his colleagues to serve as the Senate Democratic Caucus Chair for the 2025-2026 legislative session. Mark also chairs the Legislative LGBTQ+ Caucus.

During the 2025-2026 legislative session, Mark serves as the ranking Democratic member on the Committee on Government Operations, Labor, and Economic Development, and as a member of the Committee on Agriculture and Revenue and the Committee on Transportation and Local Government. 

In 2024, Mark was selected as one of 20 state leaders across the country to receive the Council of State Governments 20 Under 40 Leadership Award. 

Mark is an active member of the community and participates in nonprofit and community organizations, including serving as a Board Member of the Welty Environmental Center and previously chairing multiple committees at his church, United Church of Beloit.

Mark lives in Beloit with his husband Philip, their cat Otis, and their backyard chickens. In his free time, Mark enjoys the outdoors and baking delicious desserts made from produce in his garden.