Who has the worst WNBA season of all time?

Based on winning percentage, the 2011 Tulsa Shock had the worst WNBA record ever at 3-31.

Worst WNBA Regular Season Records

Team Year Record
1 Tulsa Shock 2011 3-31
Indiana Fever 2022 5-31
Phoenix Mercury 2023 9-31
4 Atlanta Dream 2008 4-30
5 Washington Mystics 2012 5-29
Chicago Sky 2006 5-29
Seattle Storm 2023 11-29
8 Indiana Fever 2018 6-28
Washington Mystics 2011 6-28
Tulsa Shock 2010 6-28
Charlotte Sting  2005 6-28
12 Washington Mystics 1998 3-27
New York Liberty 2018 7-27
San Antonio Stars 2016 7-27
Phoenix Mercury 2012 7-27
San Antonio Silver Stars 2005 7-27
Indiana Fever 2023 13-27
18 Indiana Fever 2021 6-26
Seattle Storm 2000 6-26
Atlanta Dream 2019 8-26
San Antonio Stars 2017 8-26
San Antonio Stars 2015 8-26
Phoenix Mercury 2003 8-26
24 Cleveland Rockers  1999 7-25
Indiana Fever 2017 9-25
Tulsa Shock 2012 9-25
San Antonio Silver Stars 2004 9-25
Washington Mystics 2003 9-25
29 Atlanta Dream 2021 8-24
Charlotte Sting  2000 8-24
New York Liberty 2019 10-24
Dallas Wings 2019 10-24
Seattle Storm 2015 10-24
Connecticut Sun 2013 10-24
Washington Mystics 2008 10-24
Minnesota Lynx 2007 10-24
Los Angeles Sparks 2007 10-24
Minnesota Lynx 2006 10-24
39 Detroit Shock 2002 9-23
Indiana Fever 2000 9-23
Dallas Wings 2016 11-23
Tulsa Shock 2013 11-23
New York Liberty 2013 11-23
Charlotte Sting  2006 11-23
New York Liberty 2006 11-23
Los Angeles Sparks 2022 13-23
Los Angeles Sparks 2023 17-23
48 Utah Starzz 1998 8-22
Sacramento Monarchs  1998 8-22
Cleveland Rockers  2002 10-22
Minnesota Lynx 2002 10-22
Washington Mystics 2001 10-22
Seattle Storm 2001 10-22
Indiana Fever 2001 10-22
Detroit Shock 2001 10-22
Portland Fire  2000 10-22
Atlanta Dream 2017 12-22
Chicago Sky 2017 12-22
Tulsa Shock 2014 12-22
Seattle Storm 2014 12-22
San Antonio Silver Stars 2013 12-22
Sacramento Monarchs  2009 12-22
Chicago Sky 2008 12-22
San Antonio Silver Stars 2003 12-22
Atlanta Dream 2022 14-22
Minnesota Lynx 2022 14-22
Chicago Sky 2023 18-22

Who has the most losses in an WNBA season?

The 2011 Tulsa Shock, 2022 Indiana Fever and 2023 Phoenix Mercury tied for the most losses in a single WNBA with 31 losses.

What is the worst record to make the WNBA Playoffs?

The worst team by winning percentage to make the WNBA playoffs is the 2021 New York Liberty, who made the playoffs with a 12-20 record. The New York Liberty lost to the Phoenix Mercury in the First Round.
Based on number of losses, the worst team to make the WNBA playoffs is the 2023 Chicago Sky, who made the playoffs with a 18-22 record. The Chicago Sky lost to the Las Vegas Aces in the First Round.