Centre-half Palmer, 23, has joined from North Ferriby United, who he helped earn promotion from National League North last season.
Vidal, 27, made 23 appearances for Wrexham last term before being released by the Welsh side in May.
Right-back East, 24, played in 25 games for Grimsby Town in 2015-16, but was allowed to leave the Mariners in May.
Details of the lengths of the trio's contracts have not been disclosed.
Find all the latest football transfers on our dedicated page.
National League club Guiseley have signed defenders Ashley Palmer and Danny East, and midfielder Javan Vidal.