Tavanagh is a townland which includes Portadown. The Shilington family lived in Tavanagh House which was in Portadown. This clearly this influenced their choice of this street name.
"Owner: Mr Shillington*, eight new streets situate off Broadway be named Benburb Street, Ebor Street, Kilburn Street, Lecale Street, Moltke Street, Rockview Street, Tavanagh Street and Glenmachan Street". (Minutes TIC, 25th May 1898). The Northern Whig of Thursday 26 May 1898 gives the additional detail that it was J.J. Shillington who requested the naming of the eight streets.
"That Mr. J. Nelson, of 42 Arthur Street, be informed, in reply to his letter of 8th inst., that the street he refers to was named Tavanagh Street by the owners in February 1898, and the Committee do not see their way to change it". (12th August 1902).