All that the bible says is that Jael was the wife of Heber the Kenite. The Kenites were a clan or small people, originally nomadic, who were not Israelites, but some of whom lived in close proximity with the Israelites. The bible records a number of cases of intermarriage; the (or a) father-in-law of Moses was apparently a Kenite, but it is not clear if this was Jethro. The Kenites may have been a part of the Midianite grouping.
God told Deborah (a prophetess and leader) that she would deliver Israel from Jabin. Deborah called Barak to make up an army to lead into battle against Jabin on the plain of Esdraelon. But Barak demanded that Deborah would accompany him into the battle. Deborah agreed but prophesied that the honour of the killing of the other army's captain would be given to a woman. Jabin's army was led by Sisera (Judg. 4:2), who fled the battle after all was lost.
Jael received the fleeing Sisera at the settlement of Heber the Kenite on the plain of Zaanaim. Jael welcomed him into her tent with apparent hospitality. She 'gave him milk' 'in a lordly dish'. Having drunk the refreshing beverage, he lay down and soon sank into the sleep of the weary. While he lay asleep Jael crept stealthily up to him, holding a tent peg and a mallet. She drove it through his temples with such force that it entered into the ground below. And 'at her feet he bowed, he fell; where he bowed, there he fell down dead'.
As a result of the killing of Sisera, God gave the victory to Israel. Jael is considered "blessed", according to the text, because of her action. Deborah's song (Judg. 5:23-27) that refers to the death of Sisera:
"Extolled above women be Jael,
The wife of Heber the Kenite,
Extolled above women in the tent.
He asked for water, she gave him milk;
She brought him cream in a lordly dish.
She stretched forth her hand to the nail,
Her right hand to the workman's hammer,
And she smote Sisera; she crushed his head,
She crashed through and transfixed his temples.
At her feet he curled himself, he fell, he lay still;
At her feet he curled himself, he fell;
And where he curled himself, let it be, there he fell dead."
Jan Saenredam engraving picturing Jael killing Sisera
Pseudo-Philo refers to Jael in the book, Liber Antiquitatum Biblicarum:
Now Jael took a stake in her left hand and approached him, saying, "If God will work this sign with me, I know that Sisera will fall into my hands. Behold I will throw him down on the ground from the bed on which he sleeps; and if he does not feel it, I know that he has been handed over." And Jael took Sisera and pushed him onto the ground from the bed. But he did not feel it, because he was very groggy.
And Jael said, "Strengthen in me today, Lord, my arm on account of you and your people and those who hope in you." And Jael took the stake and put it on his temple and struck it with a hammer.
And while he was dying, Sisera said to Jael, "Behold pain has taken hold of me, Jael, and I die like a woman."
And Jael said to him, "Go, boast before your father in hell and tell him that you have fallen into the hands of a woman."
Medieval images of Jael, mostly in illuminated manuscripts, depicted her as both a defender of Israel and a prefiguration of the Virgin Mary. This can be seen in the Stavelot Bible, the Speculus Darmstadt, as well as several other texts. When not shown in the act of killing Sisera, she carries her hammer and sometimes the spike, making her easy to identity.
In the Renaissance the subject is one of the most commonly shown in the Power of Womentopos, with other biblical women who triumphed over men, such as Judith or Delilah.  Here she was used to show the risk for men in following women, in groupings including positive figures and scenes such as Judith beheading Holofernes, but mostly ones with female "villains" such as Phyllis riding Aristotle, Samson and Delilah, Salome and her mother Herodias, The Idolatry of Solomon, and witches. More positively, Jael was included in sets of the female Nine Worthies, such as the prints by Hans Burgkmair. Ladies, who were presumably Jewish, sometimes chose to have their portraits painted as Jael, a transformation achieved by holding a hammer and spike.
In P.G. Wodehouse's novel The Code of the Woosters, the narrator Bertie Wooster mentions Jael in a description of hangover symptoms that he is experiencing: "Indeed, just before Jeeves came in, I had been dreaming that some bounder was driving spikes through my head—not just ordinary spikes, as used by Jael the wife of Heber, but red-hot ones."
Wodehouse also mentions "Jael the wife of Heber" in Galahad at Blandings. When Tipton Plimsoll shakes his head, the narrator remarks, "There are times when shaking the head creates the illusion one has met Jael the wife of Heber, incurred her displeasure and started her going into her celebrated routine."
Wodehouse also mentions "Jael, the wife of Heber" in Cocktail Time, when Frederick Twistleton describes the face of a member of the Drones Club with "...a look of ecstasy and exaltation such as Jael, the wife of Heber, must have worn when about to hammer the Brazil nut into the head of Sisera...".
Booker Prize winner A.S. Byatt's 1998 collection of short fiction, Elementals: Stories of Fire and Ice, contains a short story entitled "Jael", which is intricately related to the biblical story of Jael.
The central image of Aritha van Herk's novel The Tent Peg refers to the story of Jael and Sisera.
In the television show Weeds, there is a character named Yael who is the Admissions Director at a rabbinic school. She mentions that her name came from the story in the book of Judges.
A chapter in Martin Sugarman's book Fighting Back: British Jewry's Military Contribution in the Second World War (Valentine Mitchell, 2010) is headed "Daughters of Yael: Two Jewish Heroines of the SOE". The author uses the name to illustrate the courage of ATS Denise Bloch and WAAF Muriel Byck of the Special Operation Executive, who were killed in action operating behind German lines in France.