William Crichton or Creighton (c. 1535–1617) was a Scottish Jesuit.
He was the son of Patrick Crighton of Camnay, Perthshire; Robert Crichton, 8th Lord Crichton of Sanquhar was a relation. He matriculated in 1552 at the University of St Andrews, and in 1561 at the University of Leuven.
Crichton entered the Society of Jesus in 1561, at the same time as Edmund Hay, a cousin. He returned to Scotland to put his affairs in order.
Nicholas de Gouda, the pope's legate, was engaged in a secret embassy to Scotland in 1561–62. Crichton and Hay conducted him around Scotland, and attended the interview he had with Robert Crichton, the bishop of Dunkeld. All the ports were watched and guarded. Crichton worked with John Hay, brother of Edmund, to see to his successful escape. Crichton accompanied him to Antwerp.
Crichton spent much of the following two decades in Aquitaine, Lyon and Avignon.
Crichton returned to Scotland at the beginning of February 1582, having stopped in Normandy in January for a briefing from Robert Persons. He was accompanied by Ralph Emerson. Crichton was received into the house of George Seton, 7th Lord Seton, the only Catholic member of the royal council. He also corresponded with Esmé Stewart, 1st Duke of Lennox, cousin and guardian of James VI of Scotland, who was still a minor. To obtain an interview with Lennox, he had to be introduced into the king's palace at night, and to hide for three days in a secret chamber. The Duke promised that he would have the young king instructed in the Catholic religion, or else moved abroad. Crichton made some concessions on his side, drew up articles of agreement, and the Duke signed them.