Council Executive has approved revised plans that will deliver a new 3G sports pitch and modular changing facilities at the North Street park using £947,000 from the approved capital budget.
Previous plans for the site were for a new sports pavilion and drainage improvements, with Armadale Community Football Club (ACFC) putting forward alternative proposals for the site.
A community consultation was carried out, with around 95% of the 295 responses supporting the ACFC plans.
Leader of West Lothian Council Lawrence Fitzpatrick said: "I am delighted to confirm that close to £1 million will be invested in improving sports facilities in Armadale.
"Thanks to Armadale Community Football Club for all their hard work in preparing the proposal, along with a fully costed business plan for the operation of the new pitch and changing pavilion.
"The results from the local community were overwhelmingly in favour of the ACFC plan, so we can now move forward with delivering a fantastic new facility for Watson Park for the benefit of the Armadale community."