John I. Tay (1832 – 8 January 1892) was a Seventh-day Adventist missionary who was known for his pioneering work in the South Pacific.

The newspaper wrote "[S]o successful was he [Tay], as he claims, in his efforts to convince people there [at Pitcairn] that Saturday, the seventh day of the week, is the true and divinely appointed Sabbath, that the entire community determined to observe Saturday as their Sabbath in the future....

While at Pitcairn's Island, Mr. Tay was the guest of their head man [Simon Young], who visited this city a few years ago.

"[8] Based on Tay's report after his return, the General Conference of the Seventh-day Adventists sent a mission to Pitcairn.

The plan was to stop at Tahiti to pick up John I. Tay, then continue to Pitcairn Island where Cudney could perform the promised baptisms.

[10] The General Conference eventually paid for a ship to be built for missionary expeditions in the South Pacific.

[11] On 26 November 1890 the British ship Troop, traveling from Oregon to Cardiff, spoke to the Pitcairn and was then boarded by Tay and about 20 islanders, who sold the captain fruit and vegetables.

On 28 November 1890 the iron sailing ship Renee Rickmers of Bremerhaven was approaching Pitcairn Island when she saw the schooner, mistook it for a pirate, and rapidly stood out to sea to escape.