According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 154 words with the pattern ---TO-. That is, six letter words with 4th letter T and 5th letter O. In alphabetical order, they are:

abator

amatol

awetos

barton

bastos

bentos

bestow

bettor

bittor

boston

bottom

bouton

breton

burton

button

canton

cantor

cantos

captor

carton

cartop

castor

centos

cestoi

cestos

chaton

chiton

contos

cotton

craton

croton

custom

custos

cuttoe

dalton

danton

dattos

debtor

deuton

diatom

dittos

doctor

editor

elutor

factor

faitor

fantod

fantom

fautor

fictor

foetor

fustoc

gentoo

gustos

hector

jetton

juntos

kowtow

laptop

lector

lentor

lentos

lepton

lictor

lintol

lottos

madtom

maltol

mantos

melton

mentor

mentos

mestom

mottos

mouton

mutton

nekton

nestor

newton

nostoc

nostoi

nostos

orator

outtop

ovator

panton

pantos

parton

pastor

pestos

photog

photon

photos

phytol

phyton

pintos

pistol

piston

pistou

pluton

ponton

postop

pottos

pretor

proton

prutot

pulton

puntos

ragtop

raptor

ratton

rector

rectos

redtop

restos

rhetor

rhyton

saltos

santol

santon

santos

sartor

sector

seston

sexton

sextos

skatol

stator

suitor

tattoo

tattow

tautog

teston

tictoc

tiptoe

tiptop

toetoe

toitoi

triton

tuktoo

typtos

unstop

unstow

vector

viator

victor

vistos

wanton

wittol

wonton

xystoi

xystos

yartos

ziptop