Many words have W for a vowel, such as awe, bow, cow, dew, ewe, few gew-gaw, hew, jaw, known, lawn, maw, now, owe, pew, raw, sew, tow, vow, wow and yawn.
However, in these cases, the W is only technically a vowel, because it contributes a vowel sound, as would the letter U, from which it originates. Some words, especially Welsh, use the W as the primary vowel, much as Y is used in English. One example is the word "cwm" (valley).
(see related question)