Williams was considered one of the best offensive tackles available in the 2010 NFL Draft, and drew comparisons to Jammal Brown (who, coincidentally, would also join the Redskins that same offseason via trade). According to NFL.com's Gil Brandt, "Williams will be a first-round pick and can be a long-time starter in the NFL".
Williams was drafted fourth overall by the Washington Redskins and agreed to a six-year, US$60 million contract on July 30, 2010. In 2011, Williams was made an offensive co-captain along with veteran teammate Santana Moss. In Week 14, Williams and teammate Fred Davis were suspended for four games after failing several drug tests.