Callys has not been listed in the Top 2000 thus far. (2015 U.S. SSA RECORDS)
Callys is alike in pronunciation to Colas, Colis and Collis. Other suggested similar names are Alvys, Cable, Cacey, Cadby, Caddis, Cadmos (see Cadmus), Cael, Caelan, Caelen, Caile, Cailey, Cailin, Caily, Cairns, Caius, Caleb▲, Caley, Callan▲, Callum▲, Camillus, Camry, Capps, Carl▼, Carlo, Carlos, Carly, Carny, Carolus, Carrlos, Carwyn, Cary▼, Caryl, Casey▼, Catlin, Catullus, Cayleb, Charles▼, Charly, Claas, Claes, Claus, Cloyd, Coakly (see Coakley), Colby▼, Coll, Colla, Collby, Colle, Collen, Collie, Collin, Collins, Collyer, Colwyn, Cullan, Cullen▲, Culley, Cullin, Cully, Dallas▲, Dalles, Dallis, Hays, Kelvys (see Kelvis), Knollys, Mays, Tallis, Tallys, Talys, Wallas, Wallis and Wally. These names tend to be more frequently used than Callys.