Lawless, 31, was a free agent, having been released by Luton Town when his contract at Kenilworth Road expired at the end of last season.
He made 203 appearances during a five-and-a-half-year spell with the Hatters, who signed him from York City in 2011.
Since beginning his career at Fulham, Lawless has also had spells at Torquay United and Forest Green Rovers.
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Yeovil Town have signed midfielder Alex Lawless on a one-year deal.