The Barclays Premier League outfit have not confirmed the deal but Sporting say the teenager will move to Goodison Park until the end of the season.
A statement on the Sporting website read: "Eric Dier, central defender of the Sporting Lisbon junior team, has joined Everton on loan until June 30, 2011. This is an opportunity for him to grow in a competitive and more demanding environment."
Dier has come through the junior ranks at Sporting after his parents moved to Portugal to work when he was seven.
They have now returned to England but Dier, who has attracted interest from Manchester United, Tottenham and Arsenal in the past, stayed in Portugal to develop his game and is contracted to Sporting until 2013.
Dier is 6ft 2in and regarded as a versatile, goalscoring centre-back. He is bilingual and could be eligible for dual English-Portuguese nationality when he turns 18.
He also has footballing heritage as his grandfather, the late Ted Croker, was secretary of the Football Association from 1973-89 after playing as a defender for Charlton and Kidderminster.
Source: PA
Source: PA