Businesses
- W and A Gilbey Limited, wine importers and distillers
- W and A Roberts, builders
- W and C McDonnell Limited
- W and J Armstrong
- W and R Jacob and Company Limited
- W Drummond and Sons Limited
- W Kavanagh and Sons
- W Murphy and Company
- W Wood and Son Limited
- Walkey and McComas
- Wall Paper Manufacturing Company Limited
- Wallace Brothers Limited
- Waller and Company, printers
- Walpole Brothers Limited
- Walsall Locks and Cart Gear Limited
- Walter Brown and Company
- Walter Carson and Sons, paint and colour and varnish manufacturers
- War Department
- War Office
- Ward and Partners
- Warrack Lidington and Company
- Warren Mount Mills
- Waters Brothers and Company, tea and wine merchants
- Waverley Hotel and Restaurant
- Wayte Brothers Limited
- Webb and Webb
- Weekly Freeman
- Welford and Sons Limited, mechanical engineers
- Wells and Holohan
- Western Electric Company Limited
- Westland Row Railway Station [Pearse Station]
- Wexford Boat Club
- WG Edmonds and Company
- WG Haddock, tailor
- White Bear Hotel
- White Tomkins and Courage Limited, millers
- Whitehall Post Office
- Whiteside and Company
- Whyte and Sons Limited
- Wicklow Hotel
- William Baker Sons and Company Limited, draper
- William Bolton and Company Limited
- William Carey and Son, solicitor
- William Carter and Son
- William Curtis and Sons, brass and bellfounders
- William Dawson and Sons Limited
- William Fry and Sons, solicitors
- William G Bradley and Son, solicitors
- William Gossage and Sons Limited
- William Henry Hurcomb and Company
- William Hunter and Sons
- William Lacy and Sons
- William Laird and Company Limited, pharmaceutical chemists
- William Leckie and Company, stationers
- William M Lawrence, photographer and artists' colourman
- William Maffett and Son
- William McDowell, jeweller
- William McEvoy Limited
- William Murphy and Company
- William Rodger McTaggart, motor and cycle merchant
- William Ruddell Limited
- William Scott and Company Limited, military and merchant tailors
- William Sloan and Company
- William Smyth and Son, solicitors
- William Walsh, clockmaker
- William Watson and Sons Limited
- William Wilby, patent belt manufacturer
- William Wren and Company Limited
- Williams and Woods Limited
- Windgap Cooperative Dairy Society
- Winstanley's boot and shoe shop
- Wireless School of Telegraphy
- Wireless School RFC
- WJ Shannon and Company, solicitors
- WJ Shaw and Sons (Limerick)
- WL Ryan and Company Limited
- WO and J Wilson Limited
- Wood's Cycle Company
- Woodenbridge Hotel
- Woodhouse Hambly and Company
- Workingman's Benefit Building Society
- WW Robinson and Son Limited
- Wynn's Hotel