Baby Milestones: The Developmental Milestones of a 3 Month Old

Ergobaby
2026-03-23T16:00:56-04:00

By the time your baby reaches three months of age, an incredible transformation begins to unfold. What was once a tiny, sleepy newborn becomes a more alert, social, and engaged infant. They’re discovering their body, responding to familiar faces, and interacting with their world with curiosity and enthusiasm. These changes, often called 3 month old milestones or three month old milestones mark the transition from passive newborn behavior to intentional movement, communication, and emotional connection.

Every baby develops at their own pace, but the developmental milestones of a 3 month old tend to follow similar patterns. Below you’ll find a detailed guide to 3 month infant milestones including physical, sensory, cognitive, and social development, plus signs to watch for and ways you can support your little one through this exciting stage.

Movement & Physical Development (3 Month Infant Milestones)

During the third month, babies gain more voluntary control of their bodies. New movements become less reflexive and more purpose driven, laying the foundation for rolling, sitting, and grasping later on.

Improved Head & Neck Control

At three months, most babies can lift their head and upper chest during tummy time, using their forearms for support. This is often called symmetrical elbow support, a key marker found in many pediatric development charts.

With better head control comes the ability to look around with intention. Babies may track a parent walking past the room or follow a toy moving side to side.

Tummy Time Gets More Active

Tummy time is no longer simply tolerated, it becomes meaningful exercise. You might notice your baby:

pushing up through the forearms

opening hands rather than keeping fists clenched

experimenting with leg kicking

engaging their torso to stay balanced

These movements strengthen the neck, shoulders, spine, and core which are critical building blocks for rolling and sitting.

Supportive baby gear such as activity mats, play gyms, or bouncers can encourage natural motor development by giving babies freedom to look around, kick, and bat at toys. Bouncers in particular allow babies to explore movement safely while strengthening coordination and balance, supporting 3 month old developmental milestones.

Back Lying Movements & Fascination with Feet

On their back, babies show more symmetrical and controlled movements. Many three month olds will:

lift both legs at once to a 90 degree angle

bring hands together at midline

gently kick while studying their feet

open palms and explore fingers

This midline orientation is a major 3 month developmental milestone and helps develop balance and coordination.

Early Grasping & Toy Interaction

The tight newborn grasp reflex is fading, making room for intentional play. While babies may not reliably hold toys yet, they often:

swipe at dangling toys

bat at play gym mobiles

bring hands to mouth for self soothing

explore textures with fingers

These movements enhance fine motor development and sensory learning.

Visual & Hearing Milestones (Sensory Development)

At three months, the world becomes clearer, more colorful, and more interesting.

Tracking Faces & Objects

Babies at this age typically:

follow moving objects with both head and eyes

make longer eye contact

notice familiar faces from across the room

begin recognizing caregivers’ voices

Hand eye coordination becomes more refined, especially as babies watch their own hands in motion with intense concentration.

Sound Awareness & Early Vocalization

Hearing development expands dramatically. Most babies will:

respond to familiar voices

turn toward interesting sounds

smile at conversational tones

experiment with coos, gurgles, and babbling

This early babbling is not yet speech, but it’s the foundation of language development.

Social & Emotional Milestones

Perhaps the most heartwarming 3 month milestones are the social ones.

The Social Smile

Many caregivers see that magical first social smile around 2-3 months. By now, babies begin smiling in response to interaction, not just reflexively.

Engaging With People

Your baby may:

show excitement when adults initiate play

coo during face to face engagement

mimic facial expressions

show mild displeasure when play ends

These actions demonstrate growing emotional regulation and social awareness.

Cognitive Milestones & Learning

Three month olds are absorbing enormous amounts of information. They learn cause and effect, predict responses, and explore their environment with curiosity.

Common cognitive milestones include:

increased visual attention

longer play sessions with familiar toys

early problem solving behaviors (ex: turning head for sounds)

fascination with faces

observing hands and feet with intent

This stage lays groundwork for object permanence and communication skills later on.

Ways to Support 3 Month Baby Development

You can encourage growth with simple activities:

offer daily tummy time

engage in face to face play

narrate routine tasks

provide safe sensory toys

sing, coo, and talk frequently

allow free movement

limit container time

Small daily interactions create rich learning opportunities.

Common Challenges at 3 months

It’s also completely normal for some babies to fuss or cry when put down during this stage. Their nervous system is still developing, and many three month olds seek comfort and closeness as they adjust to longer wake windows and more stimulation.

If your baby cries when put down and you’re wondering why, this article explains common causes and soothing strategies.

3 Month Milestones: When to Consult a Pediatrician

All babies develop at different speeds, but certain signs may warrant checking in with a healthcare provider. Consider reaching out if your baby:

does not make eye contact or track faces

never smiles or responds to voice

keeps hands tightly clenched most of the time

shows stiff or jerky movements

rarely moves legs or keeps them crossed

does not lift head during tummy time

doesn’t respond to loud noises

These can be early indicators of developmental delays or sensory differences.

Celebrating Your Baby’s Third Month

Watching your baby learn, interact, and engage is one of the true joys of early parenthood. Even subtle changes, an intentional kick, a gummy smile, or a curious gaze are major achievements for your developing infant.

The developmental milestones of a 3 month old set the stage for rolling, laughing, grasping, and social play in the months ahead. So keep encouraging, playing, and observing your baby is growing in ways that are both beautiful and profound.

Activities to Support 3 Month Baby Development

By three months, your baby is gaining strength, control, and awareness. While all babies develop on their own timeline, understanding common 3 month old milestones can help you support their growth and know what to expect in the months ahead.