The 33-year-old joined the O's on an initial one-month deal in late August after impressing manager Russell Slade while training with the team during pre-season.
Rowlands, whose deal was due to expire on Friday, has made five first-team appearances for Orient this season and opened his account with a goal in the draw with Crewe last Saturday.
Slade told the club';s official website: "I'm delighted that Martin has agreed to extend his contract with the club. Martin is a good professional and an excellent player to have around the dressing room
"He has brought experience and know how to the team over the last month and it's great that he will continue to do that."
Rowlands new deal takes him through to January 27, taking in 26 games during that time.
- Russell Slade