Lia Joëlle Wälti (born 19 April 1993) is a Swiss football midfielder currently playing for Arsenal.
She previously played in Switzerland for YB Frauen, where she won the Nationalliga A and debuted in the UEFA Champions League in 2011, and Turbine Potsdam.
She is a member of the Swiss national team since August 2011.
As an Under-19 international she played the 2009 U-19 European Championship and the 2010 U-20 World Cup.