Venus is the planet of romance, luxuries and sensual pleasures. Third House is the House of Communication. With Venus in Third House one thing is certain that native would be effectively able to communicate his feelings, could be a romantic flirt, show-off luxuries as well as talk in an extravagant manner about luxuries and other finer things in life. 

     Third House is much more then board-room meetings and media nowadays. With the rise of Social Media anyone can become a high flyer in no time if Third House is in good condition. Venus is the planet of popularity among other things. As long as you are talented and not afraid to shine, Venus in Third House would give you the popularity you want. Venus blesses a native to excel in music, arts, painting, dancing and singing. And if other planets in horoscope favor then native could very well have a successful career as a musician, artist, painter, dancer or as a singer. Not just that Venus could also provide a successful career in newsroom as a news anchor or in other media. Native maybe able to go frequently on romantic long distance travels. 

     Venus in Third House provides loving siblings possibly of female gender. But even if sibling is a brother then also he would be loving and caring. Neighbors maybe rich and influential and able to help native. Venus moves very close to Mercury and Sun so if afflicted with either of them then there could be problems with communication or way too talkative personality. In a weak condition these placement of Venus could lead to negative publicity. 

     According to B. V. Raman: "Venus in Third House gives a good mind but body is weak. Native is fond of singing, dancing, music and fine arts. There could be financial troubles via over-spending and if in bad condition then it could also make him poor and broke. Also he could attract scandals and negative publicity if indeed in a bad condition. There would be loving siblings".

     Venus in Third House is not the best placement. Its very essential to keep a check on over-spending, public reputation as well as on health. If possible then prayers to Maa Santoshi are the best. She is the goddess which provides satisfaction in life. Its very necessary for those with Venus in Third House as they love to show off and they love publicty. If Venus is in a good condition then native can try prayers to Goddess Saraswati as she blesses natives with music, arts and singing skills. 

References:
Raman, Bangalore Venkata. How to Judge a Horoscope. Delhi: Motilal Banarsidass, 2014. Print.