While key midfielder Anthony Griffith was completing a move to Leyton Orient over the weekend, the first group of Micky Adams' out-of-contract players agreed new deals at the club.
Versatile defender Taylor has signed a two-year deal while striker Williamson and young goalkeeper Johnson have both put pen to paper on one-year contracts.
Vale also confirmed that winger Lewis Haldane, whose two-year spell at the club has been blighted by injury and illness, has been given a six-month deal to prove his fitness.
