The daughter of Order of Canada recipient Joseph Irvine Keeper and Anglican priest Phyllis Keeper, Tina lived the first few years of her life in the northern Manitoba
Chemawawin Cree Nation. At the age of four, she moved with her family to Winnipeg.
Keeper studied drama at the University of Winnipeg from 1989-92, completing a double major in Canadian history and theatre. Her early film credits include the National Film Board's Mistress Madeleine (1986) and Smoked Lizard Lips (1991). In 1992, Keeper joined the cast of the CBC dramatic television series North of 60, set in the fictional Indigenous Northwest Territories community of Lynx River. Her portrayal of RCMP constable and single mother Michelle Kenidi earned three consecutive Gemini Award nominations for best actress (1994, 1995, 1996). In 1997 she received a Gemini for best actress in a continuing series.
That same year, Keeper left North of 60 and concentrated on various film and television projects including Heater (1999) and In The Blue Ground (1999), for which she received the American Indian Film Festival Award for best actress. She also appeared in Trial by Fire (2000), Dream Storm (2001) and Skins (2002), which featured Eric Schweig, Graham Greene and Gary Farmer and premiered at the Sundance Film Festival. Among Keeper's works are Another Country (2003), On the Corner (2003) and Distant Drumming: A North of 60 Mystery (2003).
A social activist and a member of the Norway House Cree Nation, in 1997 Keeper hosted a relief concert to benefit victims of the Manitoba flood. She has participated in the development and implementation of various educational programs dealing with Indigenous rights and violence against women. Keeper has been particularly active as a member of a visioning committee for a Manitoba suicide prevention program. Her efforts were recognized by a National Aboriginal Achievement Award in 2004. She is also a member of the Order of Manitoba.
In January 2006, Keeper successfully ran as the federal Liberal candidate in the riding of Churchill.