Synonyms for Happily:

adv.

cheerfully (adverb)
lightheartedly, agreeably, optimistically, genially, amiably, affably, cheerily, readily, Jollily, pleasantly, gaily, gladly, cordially, complaisantly, buoyantly, spiritedly, jauntily, merrily, brightly, warmly, congenially, cheerfully, sunnily, joyfully.
fortunately (adverb)
successfully.
pleasantly (adverb)
delightfully, pleasantly, euphorically, satisfyingly, ecstatically, blissfully, gratifyingly.
successfully (adverb)
gracefully, satisfyingly, fortunately.
with joy, pleasure (adverb)
peacefully, sincerely, blissfully, joyfully, lightly, lovingly, blithely, buoyantly, agreeably, cheerfully, willingly, gaily, gladly, brightly, heartily, lightheartedly, optimistically, freely, merrily, delightfully.

adv

agreeably (adverb)
amiably, genially, affably.
cheerfully (adverb)
cheerily, cordially, optimistically, joyfully, lightheartedly, affably, buoyantly, pleasantly, spiritedly, blithely, warmly, complaisantly, mirthfully, congenially, cheerfully, genially, agreeably, brightly, Jollily, jauntily, amiably, merrily, sunnily.
fortunately (adverb)
gracefully, successfully, fortunately.
joyfully (adverb)
merrily.
pleasantly (adverb)
delightfully, blissfully, ecstatically, cheerfully, pleasantly, joyfully, satisfyingly, euphorically, gratifyingly.

n.

hooray, excellent, lovely, good, yippee, AAH, thank God/goodness/heaven(s), will wonders never cease?, GOTCHA. obligingly, only too, readily, submissively, gamely. happily (noun)
jubilantly, blithely, with happiness, mirthfully, gayly, merrily.

Other synonyms:

gracefully, readily. freely. joyously
gladly.
luckily
fortunately.
Other relevant words:
glad, gayly, mirthfully, successfully, blithely, gracefully, sincerely, fortunately, happy, jubilantly, lightly, cheerful, gladly, readily, peacefully, willingly, freely, with happiness, lovingly, gaily, pleased, heartily.

Usage examples for happily

  1. Happily Willoughby, we do not dine away from Patterne to- night." – The Complete Project Gutenberg Works of George Meredith by George Meredith
  2. It was not enough to know " and so they were married"; I must hear also how they " lived happily ever afterward." – The Land of Long Ago by Eliza Calvert Hall
  3. " But, happily I was there," said D'Artagnan, " and presently it will be my turn." – Louise de la Valliere by Alexandre Dumas, Pere