The match remained goaless after extra time, but a shootout was delayed ten minutes because of a serious injury to Huddersfield's Nigerian defender Efe Sodje.
Huddersfield win play-off final
The Terriers sealed the win by converting all four of their spot-kicks, while Mansfield scored just once.
Wayne Cordon saw his effort saved, while Liam Lawrence chipped the ball onto the top of the bar - Lee Fowler scored the vital fourth penalty which sealed the promotion for Huddersfield.
The Division Three lineup for next season has now been completed.
Relegated from Division Two:
Grimsby Town
Notts County
Rushden And Diamonds
Wycombe Wanderers
Staying in Division Three:
Boston
Bristol Rovers
Bury
Cambridge
Cheltenham
Darlington
Kidderminster
Leyton Orient
Lincoln
Macclesfield
Mansfield
Northampton
Oxford
Rochdale
Scunthorpe United
Southend
Swansea
Yeovil
Promoted from the Conference:
Chester City (Champions)
Shrewsbury Town (play-off winners)
The Division Three lineup for next season has now been completed.
Relegated from Division Two:
Grimsby Town
Notts County
Rushden And Diamonds
Wycombe Wanderers
Staying in Division Three:
Boston
Bristol Rovers
Bury
Cambridge
Cheltenham
Darlington
Kidderminster
Leyton Orient
Lincoln
Macclesfield
Mansfield
Northampton
Oxford
Rochdale
Scunthorpe United
Southend
Swansea
Yeovil
Promoted from the Conference:
Chester City (Champions)
Shrewsbury Town (play-off winners)