Myler, a long time target of Conwy Manager Chris Herbert, joins fellow former Wigan Athletic player Mike Jukes at The Morfa.
After being released by Wigan last year, Myler went on trial at Bury, before eventually signing for Warrington Town where he then moved on to Prescot Cables in the EvoStik League and established himself as a key player.
Herbert described his latest capture: "Sean is a very good attacking player, he can play wide right in the hole or centre midfield."
"He has good quality on the ball, works very hard and is brave, he will chip in with goals aswell."
"He has a old football head considering he is only 20. He is an honest player who will also do the dirty side of the game for his team mates."
"I've tried to sign for a year now. He suits our style of play, and I'm delighted to have him signed and sealed."
Myler goes straight in to the squad for tomorrow nights Word Cup game at home to Bala Town.