Both spinners underwent remedial work and re-tests of their bowling after they were suspended earlier this year, during a crackdown on illegal actions or “chucking”.
“Since being reported earlier in the year, both bowlers have remodeled their bowling actions prior to applying to have their actions re-tested,” an International Cricket Council (ICC) statement said.
“The results showed that the level of elbow extension measured for all deliveries bowled was now within the 15-degree level of tolerance permitted under the ICC regulations.”
Senanayake, 29, was reported during a one-day international on Sri Lanka’s tour to England in June, and was suspended after a bio-mechanical test a month later.
Williamson, 24, was reported during a Test on New Zealand’s tour to the West Indies in June, and was also suspended a month later.
Senanayake’s clearance is good news for Sri Lanka, whose plans for next year’s World Cup were badly hit by the spinner’s suspension.
But the ICC warned that umpires could still report both bowlers if they believe they are using a suspicious action once again.
If reported within two years of the first case, bowlers are banned for 12 months.
Since the ICC launched a crackdown on “chucking” in June, 10 bowlers have been reported and six of them suspended. Extending the arm more than 15 degrees is adjudged to give bowlers an unfair advantage.
Pakistan has been the worst hit in the crackdown, with their ace spinner Saeed Ajmal and all-rounder Mohammad Hafeez both suspended in what could affect the team’s World Cup chances. (AFP)