So, what did jesters wear in the Middle Ages and Renaissance? This set of links concentrates on pictures of those who were professionally employed as jesters or entertainers. In some cases, these individuals have had physical handicaps or mental problems. (Those who are referred to as "fools" but were not employed as such are not listed here.)

For more information on this subject, see The Jester's Mask; Fooling around the World: The History of the Jester; or these links.

Some interesting things to note: the evolution of the hood (from a simple hood with asses' ears to a multi-tailed "jester's hat"); the use of color, particolor, and dagging; and the occasional appearance of the bauble, or "jester's scepter."

• This documentation article for a Fourteenth-Century Jester's Outfit includes several miniatures from period illuminated manuscripts.
• A jester in an illustrated bible (ÖNB 1203, fol. 264r), 1341, holds a simple bauble; his hood is fairly typical for the mid-14th century, but has a contrasting lining
• A fiddling fool, wearing just a belled hood, breeches, and hose, Voeux du paon (PML G.24, fol. 32r), c. 1350
There are several medieval woodcuts which feature pictures of jesters and fools -- largely from various editions of the Ship of Fools (Navis Stultifera or Narrenschiff) by Sebastian Brandt. Here are a few online illustrations:
• Sebastian Brant: The Fool includes woodcuts from several editions and related works.
• Albrecht Durer's woodcuts for The Ship of Fools (1494) (website includes several earlier woodcuts)
• Illustrations from an edition printed in 1494 by Bergman de Olpe, Basle: Death and the miserly fool, Death and the poor fool, The demon of greed and the treasure-hunting fool
• Ship of Fools (selected illustrations from an English adaptation)
• Der Büchernarr (the book-fool), from a 1497 edition (based on this earlier illustration)
• A Fool's Table
A fool holds a small animal up to his mouth, Bible historiale (British Library Royal 15 D. III, fol. 262), early 15th century
He wears a yellow hooded garment, with bells around his waist and worn-out shoes.
A jester points out God in a cloud, the Great Bible (British Library Royal 1 E. IX, fol. 148), c. 1405-1415
Tristan de Léonois (BNF Fr. 97), first quarter of the 15th century: fols. 137v and 140 (note that the manuscript is done en grisaille; the garments are not meant to be literally white, it's just that a lot of the figures are just drawn in black & white)
A fool and falcon, Bible historiale (British Library Royal 19 D. III, fol. 266), c. 1411
Odd configuration of bells around the eared hood, echoed by other suspended bells on the gown. Blue and yellow counterchange at hood. A club instead of a bauble; lack of hose (bare legs appear in opening of gown, above his boots).
A fool dancing next to David, Breviary of John the Fearless (British Library Harley 2897, fol. 42v), c. 1413-1419
Portrait of Gonella, attributed to Jean Fouquet, second quarter of the 15th century (1440s)
Additional description of the portrait and its attribution at this BNF webpage. Gonella was the jester of Niccolo III d'Este, in Ferrara.
Illustration of Psalm 52 in a psalter (The Hague, KB, 76 F 28, fol. 81r), c. 1430
It appears that the fool's hose are pointed to a belt over his tunic; he wears an oddly-pointed hood, plays a pipe, and rides a sort of hobby-horse with a man's head.
Illustration of Psalm 52 in a bible historiale (The Hague, KB, 78 D 38 I, fol. 269v), c. 1430
The fool wears a tunic with matching eared & belled hood; his hose, in two different colors, sag around his knees, as he rides a stick like a hobby-horse.
A misericord of a jester from Kerk Sint-Pieter in Leuven, c. 1438-1442
Helen on the way to the temple of Venus, The Trojen War (ÖNB 2773, fol. 62r), c. 1445-1450; a fool dressed in grey, holding a branch of a rosebush with a garland on his head, has an ape on his back.
A grinning jester in the prayer-book of Barbara von Cilly (ÖNB 1767, fol. 257r), 1448
Cassiel and Phesona play chess, History of Alexander the Great (BNF Fr. 9342, fol. 48v), mid-15th century. The fool's blue and gold particolored garment (which appears to be a sort of pourpoint with attached hood and dagged bottom hem, and dagging below the shoulder-puffs) is worn with what apears to be footed hose with exaggerated curling point at the toe, and saggy at the waist. He carries a bauble.
Bas-de-page (Getty 2, fol. 244), c. 1450-1455
Illustration of Psalm 52 in Nicolaus de Lyra's Postilla litteralis (The Hague, KB, 128 C 8, fol. 269v), c. 1450-1475
Here we see a group of fools in various costumes; a "king" in particolor (note that the garment alternates at waist and eared hood), other men in pointed and/or belled and/or eared hoods, in various particolored garments (including hose and shoes).
Presentation of the book in The History of Alexander the Great (BNF Fr. 47, fol. 14), second half of the 15th century
An ape in a jester's ass-eared hood writes on a tablet in the margins of a book of hours (The Hague, MMW, 10 F 50, fol. 157v), c. 1460
King David and a Fool, from a bible from the workshop of the Master of the Echevinage de Rouen, 1465-1475. More visible in this larger image are the details of the fool's costume; he wears a blue cote with gold embroidery, and his belled hood (with asses' ears and a bird's head), footed joined hose, and bauble are yellow.
A tournament, Konzil von Konstanz (ÖNB 3044, fol. 146r), c. 1465-1475
A jester (and dancing men and women; possibly morris-dancers?) in the foreground of the story of St. Josaphat, Speculum Historiale (BNF Fr. 51, fol. 171), 1463
Marc and Daguenel, Tristan de Léonois (BNF Fr 102, fol. 162v), c. 1470
A fool and his master, a book of hours (British Library Harley 3000, fol. 189), c. 1470
Both the jester and his bauble wear hats with ears and a bird's head.
Gaharis receives the chapel (also here), Lancelot du Lac (BNF Fr. 112(1), fol. 45), c. 1470
Presentation scene, Des cas des nobles hommes et femmes maleureux (British Library Royal 14 E. V, fol. 5), c. 1470-1483
Efigenia and Cimone, Decameron (British Library Add. 35322.fol. 227v), c. 1475
A scene in an anecdote written by Aulus Gellius in Augustine's City of God (The Hague, MMW, 10 A 11, fol. 402v), c. 1475-1480
An eared and pointed-bottom hood (the point at the top resembles a bird's head); body garment has odd points at the elbows and bottom.
A maiden tempted by a fool from a design for a stained-glass quatrefoil, c. 1475-1490
A jester in a book of hours (Bibl. Mazarine MS 502, fol. 124), fourth quarter of the 15th century
mural with dancers and the prince-electors, at Zvikov, c. 1480-1500
Herod's Banquet, fresco in the Cappella Tornabuoni, Santa Maria Novella, Florence; Domenico Ghirlandaio, 1486-1490
The figure at the center of the foreground, with his back to us, seems to be a jester; he is a dwarf in particolored clothing which is roughly contemporary to the late 15th century.
Querfüllung mit dem Tanz der Verliebten by Israhel van Meckenem, 1490s
The jester carries a bauble or staff; his ass-eared hood buttons (or has bells sewn?) along the top, and his dagged-hem overgarment features long, hanging sleeves, and buttons at the back. He seems to have several items suspended from the back of his belt, too.
April, The Grimani Breviary, 1490-1510
A jester entertains at an outdoor gathering. His head is bare; his houppelande is similar to contemporary clothing, but with a more exaggerated collar. It seems to be particolored. He has a bauble which appears to be stuck in the back of his belt.
Jean Froissart's Chronicles, second half of the 15th century
Jesters appears in the borders along the margins of fols. 60 and 312v of BNF Fr. 2643. Another pair of fools either wrestle or dance while Isabeau of Bavaria enters Paris (BNF Fr. 2646, fol. 6)
Presentation scene, Chroniques de France et d'Angleterre (British Library Royal 14 D. V, fol. 8), late 15th century
Bold blue and white hooded garment; note the stuffed curlicue on top of the hood
The Ship of Fools, Hieronymus Bosch, 1490-1500
While the painting is intended as satire, there is at least one "real" fool among the shipmates -- the figure hunched over his bowl, perched on the trees growing out of the boat. Note the asses' ears on his hood, and the dags which are either part of his cote or attached to his belt.
Archery Festival, 1493
There are two fools at the center of the image; one wearing particolored garments in scarlet and black, and another wearing particolored garments in white and a striped fabric. While the general fit of the garments are similar, the shapes are very different. Notice that the fool in the scarlet and black seems to be wearing his pattens backwards.
A fool in a long yellow gown teases a dog with his bauble in The Installation of the First Great Masters of the Order of the Knights of St. George, c. 1495-1505
Candlestick depicting a fool, Germany, c. 1500
The Wise Man and the Fool, Pierre Sala's love poems (British Library Stowe 955, fol. 9a), early 16th century
A jester in yellow behind a messenger bringing a fish to the Duke, a fresco at Krizna Gora, 1502
A fool in a breviary of the priory of Saint-Lô of Rouen (Bibl. Sainte-Geneviève MS 1266, fol. 162), first quarter of the 16th century
The Flower of Virtue, 16th century
A fool wearing a loose white-pink garment over blue hose; he wears a hood particolored blue and gold, with a bell at the point on the chest. He carries a bauble (note the small head on a thin black rod).
The Betley Window, ca. 1509
The jester carries a bauble. His ass-eared hood comes to a curved point in front; there are large bells suspended from the elbows of his reddish cote, and from a point at the side or back of the lower hem (one supposes there is a similar point on the other side, too). His hose, black and gold, are further accessorized by anklets of bells.
Tournament scene by Jörg Breu the Elder, c. 1510-1515
A misericord from the Kerk O.L.Vrou in Aarschot, c. 1515-1525
The Lancaster Castle Panel, early to mid-16th century
The fool's hood comes to two horn-like points, from which bells seem to have been suspended; he carries a bauble, too. His cote seems to come to a point in the rear, from which a bell is suspended.
Reform minister officiating at the marriage of the fool and the she-devil, from Von dem grossen Lutherischen Narren, 1518
Details from the January, February, April, and September sections of Die Augsburger Monatsbilder, Germany, 1520s
Mural by Albrecht Altdorfer, c. 1530-1540
The amorous old man, c. 1530-1560
Good detail on the bird-headed (and eared!) hood, and bauble
Henry VIII as David, with his jester Will Somers, Psalter of Henry VIII (British Library Royal 2 A. XVI, fol. 63v), c. 1530-1547; Will Somers also appears in this portrait (possibly a composite) with Henry and his daughter Mary, and in this portrait of the family of Henry VIII painted c. 1545 (Will appears in the doorway at far right), and this portrait of Henry VIII and his children (see article).
A dancing fool by Hans Sebald Beham
Stained glass: Jester with the arms of Bartholomew Linck, 1553
Jester's scepter in ivory and silk, from the second half of the 16th century. (More photos here, here, and here.)
The Battle of Carnival and Lent, Pieter Brueghel the Elder
There is a fool at the center of the picture; he is the figure in the particolored garment (black & white striped on one side, red on the other) which covers him from head to knee, with asses' ears on his head. (See Fools at Play for woodcuts based on other Brueghel paintings of fools.)
Tournament book recording jousts in Nuremburg from 1446 to 1561
A jester painted on a wooden spoon, 16th century
The Triumph of Death, Pieter Brueghel the Elder, 1562
A fool diving under the table on the left side of this detail wears a hooded garment (probably with ass's ears) -- or possibly a garment and separate hood -- both of a red and white diamond pattern, as well as long stockings covering his legs.
The entertainers in The Wedding at Cana by Paolo Veronese, 1563
The Gold-Fool (miser), Food-Fool (glutton), Natural Fool, and Jester in the Ständebuch, 1568
A jester and other entertainers knock on a door from a wedding-dish, 1572
Feast in the House of Levi, Paolo Veronese, 1573
Several shorter figures which may be either entertainers or young servants. One is definitely a jester; a seated figure in the foreground, towards the left of the center of the painting, who seems to be teasing a slightly taller servant.
Richard Tarlton, a jester to Elizabeth I, John Scottowe's Alphabet (British Library Harley 3885, fol. 19), after 1588
Village Fair by Pieter Brueghel the Younger
Jester's bauble in carved ivory with original bells, c. 1600
Jester's scepter in carved ivory (with velvet and gold fabrics) from the first half of the 17th century.
Velazquez's 17th century portraits of Spanish court dwarves and jesters: Court Dwarf Don Antonio el Ingls; Diego de Acedo (El Primo); The Dwarf Francisco Lezcano, Called "El Nino de Vallecas"; The Jester Known as Don Juan de Austria; The Dwarf Don Juan Calabazas, called Calabacillas; and The Dwarf Sebastian de Morra. There are also dwarves in Las Meninas and Prince Baltasar Carlos with a Dwarf.