Fonte has not featured for the Hammers since November, owing to a knee injury.
However, the Portuguese centre-back is back and available for selection again.
“I’ve said before and I’ll say it again – I’m ready,” Fonte said. “Whenever the manager needs me, I’m ready and just want to be out there helping the boys, producing good performances.
“All I am focused on now is helping the team and helping us get up the table.”
Fonte’s return to West Ham boosts Moyes’ options at the back, at a crucial stage of the season.
The Hammers have suffered badly with injuries so far this campaign, but a number of players are returning now.
Whether Fonte will be used as a regular remains to be seen, as the Hammers have been in solid form in the league over recent times.
West Ham have avoided defeat in six of their last seven matches, although they were beaten 3-1 by Brighton & Hove Albion in their last outing.